The pediatric chronic pain clinic nurse’s communication challenge
The pediatric chronic pain clinic nurse works in a specialty where every treatment recommendation challenges the family’s most fundamental model of illness: that real pain has a structural cause visible on imaging, that more investigation reveals hidden disease, and that medication eliminates pain. Three recurrent misalignments define the communication challenge in the pediatric chronic pain clinic with particular urgency.
The first is the treatment paradox in CRPS. A child with complex regional pain syndrome is in genuine, severe pain — allodynia makes light touch agonizing, temperature asymmetry is visible, and the ankle that healed on MRI six weeks ago now cannot tolerate the weight of a bed sheet. The treatment is physical therapy. The child cries during sessions. The family has stopped therapy. The nurse must explain that the child’s pain during PT is not a signal that the therapy is harmful — it is the expected response of a central nervous system in which dorsal horn wind-up has lowered the firing threshold of pain-processing neurons so that normal, non-noxious stimuli activate nociceptive pathways. Graded desensitization PT is the only intervention that reverses this central sensitization; immobilization deepens it by allowing the cortical remapping that develops when the affected limb’s sensory input is absent to progress unchecked.
The second is the opioid expectation in AMPS. Amplified musculoskeletal pain syndrome produces constant, severe, diffuse pain that is entirely real and entirely resistant to standard analgesia — yet the complete laboratory and imaging workup is normal, and the treatment is an intensive interdisciplinary physical therapy and CBT program without opioids. The family experiences the absence of a structural diagnosis as disbelief and the absence of opioids as abandonment. The nurse must explain the concept of nociplastic pain — the third mechanistic category of pain, where descending inhibitory pathways fail to suppress dorsal horn nociceptive output — and that opioids do not repair failed descending inhibition. They substitute for one component of it in the short term and worsen central sensitization through opioid-induced hyperalgesia in the long term. The intensive rehabilitation program achieves approximately 80 percent return to full activity by rebuilding descending inhibitory tone through exercise-induced endorphin and BDNF release.
The third is the investigation escalation in FAPD. A child with functional abdominal pain disorder has had three emergency department visits, two abdominal CT scans, and a negative Helicobacter pylori test. The mother wants a colonoscopy because she has read about Crohn’s disease. The fecal calprotectin is 42 μg/g. The nurse must explain that calprotectin directly measures intestinal neutrophil and macrophage activity — the inflammation required for Crohn’s disease to produce its findings — and that a level of 42 provides strong evidence against active intestinal inflammation. FAPD is a positive diagnosis on Rome IV criteria representing visceral hypersensitivity of the brain-gut axis, not a diagnosis of exclusion. A colonoscopy would show normal mucosa and cannot diagnose FAPD, because FAPD is a functional change in the sensitivity of the enteric nervous system, not a structural change visible to the colonoscopist.
Three conversations from the pediatric chronic pain clinic:
Scenario 1: Sofía Herrera-Torres — 13 years old, Houston, Texas
Sofía Herrera-Torres had been playing center midfield in a club soccer match in late July when she planted her right foot and felt her ankle roll. The sprain was graded moderate at the urgent care clinic — swelling, tenderness over the anterior talofibular ligament, no fracture on plain radiographs. She was given a brace and told to follow up in two weeks. The swelling and ATFL tenderness resolved over six weeks. The follow-up MRI at eight weeks showed complete healing with no ligamentous discontinuity, no bone marrow edema.
But the pain had not resolved. By September, Sofía reported burning pain in the right ankle that was worse than the acute injury. The dorsum of her right foot had become exquisitely sensitive to light touch — the pressure of a sock produced visible distress. The right ankle and foot were cooler than the left by 1.8 degrees Celsius on infrared thermometry, and the skin over the dorsal foot showed a mottled purple livedo reticularis pattern that was not present on the left. She had been weight-bearing minimally and had stopped attending school in person, attending virtually from home.
The pediatric rheumatology referral had ruled out inflammatory arthritis: no synovitis, no elevated inflammatory markers, negative ANA, negative RF. The orthopedics follow-up had confirmed complete ligamentous healing. The diagnosis was CRPS Type I — complex regional pain syndrome developing after a soft-tissue injury with no documented nerve injury, meeting Budapest criteria: allodynia and hyperalgesia in the sensory category; temperature asymmetry greater than 1 degree Celsius and purple skin discoloration in the vasomotor category; edema in the sudomotor category; and decreased range of motion with guarding in the motor category. Two symptom categories and two sign categories confirmed — Budapest criteria met.
The pediatric chronic pain clinic had prescribed a structured graded desensitization PT program beginning with graded motor imagery and mirror visual feedback, advancing to progressive tactile exposure and weight-bearing. Sofía had attended four sessions. At the fourth session, the PT had begun progressive tactile stimulation of the dorsum of the foot with soft materials, and Sofía had become acutely distressed, crying and refusing to continue. Her parents Alejandro, a construction supervisor, and Marta, a medical biller, had taken her out of the session and driven straight to the pediatric chronic pain clinic.
“Esto no está funcionando,” Alejandro said to pediatric chronic pain clinic nurse Gabriela Méndez-Fuentes, who had seen them in the waiting area. “El pie de Sofía está curado según el MRI. No hay nada roto. Y el fisioterapeuta la está lastimando más. No lo voy a seguir permitiendo. Quiero que le receten algo para el dolor — morfina, hidrocodona, lo que sea — y que le dejen el pie en paz.” (This is not working. Sofía’s foot is healed according to the MRI. Nothing is broken. And the physical therapist is hurting her more. I will not keep allowing this. I want her to be prescribed something for the pain — morphine, hydrocodone, whatever — and to leave her foot alone.)
Sofía sat next to him, her right foot extended forward, not touching the floor. Marta had her arm around her daughter’s shoulders.
Gabriela sat across from them. “Sofía, antes de responderle a tu papá, quiero preguntarte algo. Cuando el fisioterapeuta te toca el pie — la sensación que sientes, ¿se parece al dolor que tenías el día que se torciste el tobillo?” (Sofía, before responding to your dad, I want to ask you something. When the physical therapist touches your foot — the sensation you feel, does it resemble the pain you had the day you sprained your ankle?)
Sofía thought for a moment. “No. Es diferente. El día que me lo torci me dolía porque hice algo. Este dolor — es como cuando te toca algo suave y sientes que te están quemando.” (No. It’s different. The day I sprained it, it hurt because I did something. This pain — it’s like when something soft touches you and you feel like you’re being burned.)
“Eso es exactamente lo que necesito que entienda su papá,” Gabriela said to Alejandro. “Lo que Sofía acaba de describir — que un tóque suave produce una sensación de quemadura — tiene un nombre clínico. Se llama alodinía. Y la alodinía no viene del pie — viene de lo que le pasó al sistema nervioso de Sofía después de la lesión.” (That is exactly what I need her father to understand. What Sofía just described — that a soft touch produces a burning sensation — has a clinical name. It’s called allodynia. And the allodynia doesn’t come from the foot — it comes from what happened to Sofía’s nervous system after the injury.)
Alejandro crossed his arms. “¿Qué le pasó al sistema nervioso?” (What happened to the nervous system?)
“Cuando Sofía se torció el tobillo, las fibras nerviosas del dolor en el pie — las fibras C — enviaron señales de dolor intenso a la médula espinal. Eso es normal. Lo que no era normal es lo que ocurrió después: esas señales activaron un proceso en la médula espinal llamado potenciación a largo plazo en las neuronas que procesan el dolor. Es el mismo proceso molecular que forma recuerdos en el cerebro — las sinapsis de las neuronas del dolor se reforzaron y bajaron su umbral de activación. Ahora esas neuronas en la médula espinal de Sofía — que normalmente solo se activan con estímulos intensamente dolorosos — se activan con estímulos que normalmente no son dolorosos en absoluto: el tóque suave, el calor moderado, el peso de una media. Eso es la sensibilización central: el volumen del sistema del dolor se quedó en máximo.” (When Sofía sprained her ankle, the pain nerve fibers in the foot — the C fibers — sent intense pain signals to the spinal cord. That is normal. What was not normal is what happened after: those signals activated a process in the spinal cord called long-term potentiation in the pain-processing neurons. It’s the same molecular process that forms memories in the brain — the synapses of the pain neurons strengthened and lowered their firing threshold. Now those neurons in Sofía’s spinal cord — which normally only activate with intensely painful stimuli — activate with stimuli that are normally not painful at all: light touch, moderate warmth, the weight of a sock. That is central sensitization: the pain system’s volume got stuck at maximum.)
Marta had put down her phone. “¿Y el reposo no puede revertir eso?” (And rest cannot reverse that?)
“Esa es la parte más difícil de explicar. El reposo empeora la sensibilización central en el SDRC. Cuando un miembro está inmovilizado — especialmente cuando su única aportación sensorial al cerebro es dolor — el área del cerebro que representa ese miembro empieza a reorganizarse. Los investigadores llaman a esto remapeo cortical: las áreas corticales adyacentes al mapa sensorial del pie de Sofía empiezan a invadir ese territorio porque el pie no está enviando señales normales. Ese remapeo hace que la discrepancia entre lo que el cerebro espera y lo que recibe cuando el pie es tocado se vuelva más grande, no más pequeña. El SDRC en niños que son inmovilizados durante meses progresa, no mejora. La única intervención con evidencia que revierte la sensibilización central es la fisioterapia de desensibilización gradual.” (That is the hardest part to explain. Rest worsens central sensitization in CRPS. When a limb is immobilized — especially when its only sensory contribution to the brain is pain — the area of the brain that represents that limb begins to reorganize. Researchers call this cortical remapping: the cortical areas adjacent to the sensory map of Sofía’s foot begin to invade that territory because the foot is not sending normal signals. That remapping makes the discrepancy between what the brain expects and what it receives when the foot is touched larger, not smaller. CRPS in children who are immobilized for months progresses, it does not improve. The only intervention with evidence that reverses central sensitization is graded desensitization physical therapy.)
Alejandro had been leaning forward. “¿Y la morfina?” (And morphine?)
“Los opioides actúan en receptores mu en la médula espinal — reducen la transmisión de señales de nociceptores activos. Pero la sensibilización central en el SDRC está mediada por receptores NMDA — un mecanismo diferente, que los opioides no abordan de la misma manera. Y existe un fenómeno llamado hiperalgesia inducida por opioides: el uso crónico de opioides activa los receptores NMDA de la médula espinal por vías indirectas que paradojicamente aumentan la sensibilización al dolor en lugar de reducirla. Los centros de dolor pediátrico no prescriben opioides en el SDRC de niños porque empeorarían el mecanismo subyacente.” (Opioids act on mu receptors in the spinal cord — they reduce the transmission of signals from active nociceptors. But central sensitization in CRPS is mediated by NMDA receptors — a different mechanism, which opioids do not address in the same way. And there is a phenomenon called opioid-induced hyperalgesia: chronic opioid use activates spinal cord NMDA receptors through indirect pathways that paradoxically increase pain sensitization rather than reducing it. Pediatric pain centers do not prescribe opioids in pediatric CRPS because they would worsen the underlying mechanism.)
Sofía had been listening. “Entonces el dolor que siento cuando me tocan el pie — ¿no es del pie?” (So the pain I feel when my foot is touched — it’s not from the foot?)
“Es del sistema nervioso que aprendió — incorrectamente — que el pie es peligroso. Y la fisioterapia le está enseñando al sistema nervioso que el pie puede ser tocado, que puede moverse, que puede recibir temperatura, y que ninguna de esas cosas es una amenaza. Cada sesión es más difícil de lo que parece porque está desafiando al sistema nervioso sensibilizado. Y cada sesión también avanza el proceso de recalibración.” (It is from the nervous system that learned — incorrectly — that the foot is dangerous. And the physical therapy is teaching the nervous system that the foot can be touched, that it can move, that it can receive temperature, and that none of those things is a threat. Each session is harder than it looks because it is challenging the sensitized nervous system. And each session also advances the recalibration process.)
Alejandro looked at his daughter for a long moment. “¿Puedes seguir con la fisioterapia?” (Can you continue with the physical therapy?)
Sofía looked at the floor — at her right foot, extended slightly away from the weight of her own posture. “Si es para que el pie aprenda de nuevo — sí,” she said. “Pero quiero que me expliquen por qué cada cosa antes de hacerla.” (If it’s for the foot to learn again — yes. But I want them to explain why each thing before they do it.)
“Eso es exactamente lo que el fisioterapeuta debe hacer contigo,” Gabriela said. “Voy a hablar con el equipo ahora.” (That is exactly what the physical therapist should do with you. I’m going to talk with the team now.)
Scenario 2: Diego Ramírez-Cisneros — 11 years old, San Antonio, Texas
Diego Ramírez-Cisneros had been a pitcher on his Little League team and a strong student until March of last year, when he began complaining of aching pain in both legs. His parents had taken him to his pediatrician, then to a sports medicine physician, then to pediatric rheumatology. The rheumatology evaluation had been thorough: ANA negative, anti-dsDNA negative, RF and anti-CCP negative, CRP less than 0.3 mg/L, ESR 12 mm/hr, normal CBC and comprehensive metabolic panel, normal uric acid. Musculoskeletal ultrasound showed no synovitis or enthesitis in the bilateral ankles, knees, or hips. MRI of the bilateral hips and lumbar spine showed no bone marrow edema, no stress fracture, no inflammatory signal. Nerve conduction studies and electromyography showed no neuropathy. The rheumatologist’s note was unambiguous: no inflammatory, infectious, metabolic, structural, or neuropathic cause identified. Diagnosis: amplified musculoskeletal pain syndrome, diffuse distribution.
By the time Diego arrived at the pediatric chronic pain clinic nine months after onset, he was missing four days of school per week, using a wheelchair for distances beyond fifty meters, sleeping poorly from pain, and had stopped all athletic activity. His father Ricardo worked as a shift manager at a warehouse distribution center. His mother Gloria was an administrative coordinator at a dental office. They had sat through five specialist evaluations telling them nothing was structurally wrong, and they had become progressively more frustrated with each normal result. Ricardo had come to the chronic pain clinic appointment with a specific request.
“Mi hijo lleva nueve meses con dolor constante de 8 sobre 10,” Ricardo said to pediatric chronic pain clinic nurse Carlos Morales-Espinoza. “No puede ir a la escuela. No puede caminar tres cuadras. Todos los estudios están normales y nadie le da nada para el dolor. Yo sé que existe la morfina. Yo sé que existe la hidrocodona. Lo único que quiero saber es por qué no se los dan a mi hijo.” (My son has had constant 8-out-of-10 pain for nine months. He can’t go to school. He can’t walk three blocks. All the studies are normal and no one gives him anything for pain. I know morphine exists. I know hydrocodone exists. All I want to know is why they don’t give them to my son.)
Gloria was beside him. “Si el dolor es real — y es real, lo vemos todos los días — tiene que haber una medicina.” (If the pain is real — and it is real, we see it every day — there has to be a medicine.)
Diego sat in the chair across the room, head down, legs extended, not making eye contact.
Carlos set aside the chart. “Primero quiero que los dos sepan algo que no es negociable: el dolor de Diego es completamente real. Los estudios de neuroimagen funcional en niños con el diagnóstico de Diego muestran activación aumentada y real en las áreas del cerebro que procesan el dolor cuando se les aplican estímulos que no son dolorosos en niños sanos. Nadie en este clínica cree que Diego está exagerando o fingiendo. Empezamos desde ahí.” (First I want you both to know something that is not negotiable: Diego’s pain is completely real. Functional neuroimaging studies in children with Diego’s diagnosis show real, increased activation in the brain areas that process pain when stimuli are applied that are not painful in healthy children. No one in this clinic believes Diego is exaggerating or pretending. We start from there.)
Ricardo uncrossed his arms slightly. Gloria put her hand on the chair arm.
“La medicina del dolor tiene tres categorías de dolor. Primera: dolor por daño en el tejido — una fractura, una apendicitis, una herida. El tejido está dañado, los nociceptores del tejido se activan, la señal viaja a la médula espinal. Los opioides funcionan bien aquí porque actúan en los receptores que procesan esa señal. Segunda: dolor por daño en el nervio — una neuropatía, una lesíon nerviosa. El nervio está dañado y genera señales anormales. Los opioides tienen efecto parcial aquí. Tercera categoría — la más reciente, reconocida formalmente por la Asociación Internacional para el Estudio del Dolor en 2017: dolor nociplastico. El tejido no está dañado. El nervio no está dañado. El dolor es generado por el sistema nervioso central cuando las vías que normalmente inhiben el dolor no están funcionando correctamente. El diagnóstico de Diego es este tercer tipo.” (Pain medicine has three categories of pain. First: pain from tissue damage — a fracture, appendicitis, a wound. Tissue is damaged, the tissue’s nociceptors activate, the signal travels to the spinal cord. Opioids work well here because they act on the receptors that process that signal. Second: pain from nerve damage — a neuropathy, a nerve injury. The nerve is damaged and generates abnormal signals. Opioids have partial effect here. Third category — the most recent, formally recognized by the International Association for the Study of Pain in 2017: nociplastic pain. Tissue is not damaged. The nerve is not damaged. The pain is generated by the central nervous system when the pathways that normally inhibit pain are not functioning correctly. Diego’s diagnosis is this third type.)
Gloria had her notebook. “¿Las vías que inhiben el dolor — cuáles son?” (The pathways that inhibit pain — what are they?)
“El cerebro tiene sistemas descendentes — vienen del cerebro hacia la médula espinal — que en condiciones normales funcionan como filtros: reducen las señales de dolor que sube desde el cuerpo, especialmente cuando el dolor no representa una amenaza real. Estos sistemas usan serotonina, noradrenalina, y opioides endógenos — los que el cuerpo produce. En Diego, por razones que están siendo investigadas activamente, estos sistemas no están suprimiendo la señal del dolor con la eficacia normal. La médula espinal amplifica lo que recibe, y Diego siente dolor de estímulos — movimiento, presión, postura — que no deberían activar esas neuronas.” (The brain has descending systems — coming from the brain toward the spinal cord — that under normal conditions function as filters: they reduce pain signals coming up from the body, especially when the pain does not represent a real threat. These systems use serotonin, noradrenaline, and endogenous opioids — those the body produces. In Diego, for reasons being actively investigated, these systems are not suppressing the pain signal with normal efficacy. The spinal cord amplifies what it receives, and Diego feels pain from stimuli — movement, pressure, posture — that should not activate those neurons.)
Ricardo had been listening with his jaw set. “¿Y los opioides remplazan esos opioides endógenos que faltan?” (And opioids replace those missing endogenous opioids?)
“Esa es la lógica — y la razón por la que la pregunta es completamente razonable. La respuesta es no, y es importante entender por qué. Los opioides exogenos — morfina, hidrocodona — se unen a los receptores mu en la médula espinal y producen algo de supresión del dolor a corto plazo. Pero el uso continuo de opioides activa un proceso en la médula espinal donde se produce dinorfina A — un opioide endógeno que paradojicamente activa receptores NMDA, los mismos que mediaron la sensibilización central. También activa receptores Toll-like 4 en las células gliales de la médula espinal, que liberan citoquinas proinflamatorias que sensibilizan más a las neuronas del dolor. El resultado: hiperalgesia inducida por opioides — el uso prolongado de opioides en dolor nociplastico como el de Diego empeora la sensibilización al dolor en lugar de mejorarla. Hay niños con SDMA que fueron puestos en opioides y terminaron peor. Por eso los centros especializados en dolor pediátrico — el Cincinnati Children’s, el Boston Children’s, el Children’s Hospital of Philadelphia — no usan opioides en este diagnóstico.” (That is the logic — and the reason why the question is completely reasonable. The answer is no, and it is important to understand why. Exogenous opioids — morphine, hydrocodone — bind to mu receptors in the spinal cord and produce some pain suppression in the short term. But continuous opioid use activates a process in the spinal cord where dynorphin A is produced — an endogenous opioid that paradoxically activates NMDA receptors, the same ones that mediated central sensitization. It also activates toll-like receptor 4 on spinal cord glial cells, which release pro-inflammatory cytokines that further sensitize pain neurons. The result: opioid-induced hyperalgesia — prolonged opioid use in nociplastic pain like Diego’s worsens pain sensitization rather than improving it. There are children with AMPS who were put on opioids and ended up worse. That is why specialized pediatric pain centers do not use opioids for this diagnosis.)
Gloria had stopped writing. “¿Entonces qué funciona?” (So what works?)
“El Programa de Rehabilitación Intensivo Interdisciplinario del Dolor — PRIDI. Fisioterapia y terapia ocupacional 3 a 5 días por semana más terapia cognitivo-conductual. El ejercicio activa la liberación de endorfinas y BDNF en el cerebro que reconstruyen las vías inhibitorias descendentes que no están funcionando bien en Diego. La exposición gradual al movimiento le enseña al sistema nervioso sensibilizado que el movimiento no es peligroso, reduciendo la amplificación de la médula espinal. La terapia cognitivo-conductual extingue el ciclo de evitación por miedo — el comportamiento de proteger el miembro, evitar el movimiento, faltar a la escuela — que perpetúa la sensibilización. El doctor Sherry publicó resultados en 103 niños con SDMA tratados con fisioterapia intensiva: el 80 por ciento regresó completamente a la escuela y los deportes dentro del período del programa.” (The Intensive Interdisciplinary Pain Rehabilitation Program — IIPR. Physical and occupational therapy 3 to 5 days per week plus cognitive behavioral therapy. Exercise activates the release of endorphins and BDNF in the brain that rebuild the descending inhibitory pathways that are not functioning well in Diego. Gradual exposure to movement teaches the sensitized nervous system that movement is not dangerous, reducing spinal cord amplification. Cognitive behavioral therapy extinguishes the fear-avoidance cycle — the behavior of protecting the limb, avoiding movement, missing school — that perpetuates the sensitization. Dr. Sherry published outcomes in 103 children with AMPS treated with intensive PT: 80 percent returned completely to school and sports within the program period.)
Ricardo was quiet for a long moment. He looked at Diego, who had been listening with his head down but had, at some point, straightened slightly in the chair. “Diego — ¿te explicaron alguna vez que el problema está en el sistema nervioso, no en los músculos?” (Diego — did anyone ever explain to you that the problem is in the nervous system, not the muscles?)
“No,” Diego said. “Me decían que los estudios eran normales. Eso era todo.” (No. They told me the studies were normal. That was all.)
“Ahora lo saben todos,” Carlos said. “El próximo paso es hablar del programa.” (Now everyone knows. The next step is to talk about the program.)
Scenario 3: Valentina Cruz-Espinoza — 9 years old, Dallas, Texas
Valentina Cruz-Espinoza had had her first episode of abdominal pain at age seven — a periumbilical ache that lasted forty minutes and then resolved completely. The pediatrician at the time had examined her, found a soft abdomen with no guarding, no rebound, normal bowel sounds, and had diagnosed a likely viral gastroenteritis. Valentina had been fine for three weeks, then the episodes had recurred. By the time her mother Carmen, a dental hygienist, had brought her to the emergency department for the first visit at age eight, Valentina had been having three or more episodes per week for six months. The ED evaluation had included a complete blood count, a comprehensive metabolic panel, a urinalysis, and an abdominal ultrasound. All normal. The ED note read: “functional abdominal pain — follow up with pediatrician.”
The second ED visit came after a particularly severe episode at school; a teacher had called 911 because Valentina was doubled over and could not straighten. The second ED evaluation included an abdominal CT scan. Normal. The third ED visit, three months later, included a second CT scan. Normal again. A Helicobacter pylori stool antigen test had been ordered after the third ED visit: negative. Fecal calprotectin had been ordered by the pediatrician after reviewing the charts: 42 μg/g. Carmen had brought a printed summary of the three ED visits, both CT reports, and the calprotectin result to the pediatric chronic pain clinic appointment.
“Tres urgencias, dos tomografías, todo normal,” Carmen said to pediatric chronic pain clinic nurse Patricia Sánchez-Fuentes. “He leído sobre la enfermedad de Crohn. Los síntomas cuadran — dolor abdominal recurrente, en niños, que no se explica. Quiero que le hagan una colonoscopía para descartarlo definitivamente.” (Three emergency visits, two CT scans, everything normal. I’ve read about Crohn’s disease. The symptoms match — recurrent abdominal pain, in children, unexplained. I want her to have a colonoscopy to definitively rule it out.)
Valentina sat beside her, leaning on her mother’s shoulder, watching the nurse.
“La preocupación por el Crohn es completamente válida,” Patricia said. “El Crohn en niños puede presentarse exactamente así — dolor abdominal recurrente, sin otras señales claras al principio. Quiero mostrarle el resultado del calprotectal y explicar lo que significa, porque ese resultado ya nos da información directa sobre el Crohn.” (The concern about Crohn’s is completely valid. Crohn’s in children can present exactly like this — recurrent abdominal pain, without other clear signs at first. I want to show you the calprotectin result and explain what it means, because that result already gives us direct information about Crohn’s.)
Carmen leaned forward as Patricia opened the lab summary.
“El calprotectal es una proteína que está dentro de los neutrófilos y macrófagos — las células inmunes que infiltran el intestino cuando hay inflamación activa, como en la enfermedad de Crohn o la colitis ulcerativa. Cuando esas células mueren en la mucosa intestinal inflamada, liberan calprotectal dentro del intestino, y pasa a las heces. El nivel de calprotectal en las heces es una medida directa de cuánta actividad inflamatoria hay en la mucosa intestinal ahora mismo. Un análisis de estudios clínicos encontró que el calprotectal tiene una sensibilidad del 89 por ciento y una especificidad del 70 por ciento para enfermedad inflamatoria intestinal en niños con un umbral de más de 200 microgramos por gramo. El de Valentina es 42 — muy por debajo de ese umbral. Eso no es una prueba absoluta de que no hay Crohn, pero es evidencia sólida de que no hay inflamación intestinal activa del tipo que produce la enfermedad de Crohn o la colitis ulcerativa ahora mismo.” (Calprotectin is a protein inside neutrophils and macrophages — the immune cells that infiltrate the intestine when there is active inflammation, as in Crohn’s disease or ulcerative colitis. When those cells die in the inflamed intestinal mucosa, they release calprotectin into the intestine, and it passes into the stool. The level of calprotectin in the stool is a direct measurement of how much inflammatory activity there is in the intestinal mucosa right now. A meta-analysis of clinical studies found that calprotectin has 89 percent sensitivity and 70 percent specificity for IBD in children at a threshold of greater than 200 micrograms per gram. Valentina’s is 42 — well below that threshold. That is not absolute proof that there is no Crohn’s, but it is strong evidence that there is no active intestinal inflammation of the type that produces Crohn’s disease or ulcerative colitis right now.)
Carmen was quiet for a moment. “¿Y la colonoscopía podría encontrar algo que el calprotectal no detecta?” (And could the colonoscopy find something the calprotectin doesn’t detect?)
“Esa es la pregunta correcta. La colonoscopía vería la mucosa del intestino grueso y el íleon terminal. Si el calprotectal fuera 380 — que indicaría inflamación activa — la colonoscopía sería el siguiente paso lógico. Con un calprotectal de 42, lo que la colonoscopía encontraría es mucosa normal — eso es lo que esperamos dado el calprotectal. Además, el Crohn puede afectar el intestino delgado, que la colonoscopía no puede ver — eso requiere una endoscopía de cápsula o una entero-RMN. Una colonoscopía bajo anestesia o sedación profunda en una niña de 9 años requiere dos días de preparación intestinal con líquidos claros y laxantes osmóticos, anestesia general o sedación profunda, y recuperación post-procedimiento. Valentina ya ha tenido dos tomografías con radiación ionizante. El calprotectal de 42 nos permite no exponer a Valentina a otro procedimiento invasivo para obtener el mismo resultado que ya tenemos: ausencia de inflamación intestinal activa.” (That is the right question. The colonoscopy would see the mucosa of the large intestine and the terminal ileum. If the calprotectin were 380 — indicating active inflammation — colonoscopy would be the logical next step. With a calprotectin of 42, what the colonoscopy would find is normal mucosa — that is what we expect given the calprotectin. Additionally, Crohn’s can affect the small intestine, which colonoscopy cannot see — that requires a capsule endoscopy or MR enterography. A colonoscopy under general anesthesia or deep sedation in a 9-year-old requires two days of bowel preparation with clear liquids and osmotic laxatives, general anesthesia or deep sedation, and post-procedure recovery. Valentina has already had two CT scans with ionizing radiation. The calprotectin of 42 allows us not to expose Valentina to another invasive procedure to obtain the same result we already have: absence of active intestinal inflammation.)
Carmen exhaled. “¿Entonces cuál es el diagnóstico?” (So what is the diagnosis?)
“Trastorno de dolor abdominal funcional — criterios Roma IV. Es un diagnóstico positivo, no un diagnóstico de exclusión. Los criterios Roma IV son un sistema de diagnóstico clínico que existe porque los trastornos funcionales gastrointestinales son condiciones reales con mecanismos bien estudiados. El mecanismo en el caso de Valentina es la hipersensibilidad visceral: el intestino tiene su propio sistema nervioso — los investigadores lo llaman el ‘segundo cerebro’ — con aproximadamente 500 millones de neuronas en dos redes llamadas el plexo entérico de Auerbach y el plexo submucosal de Meissner. Esas neuronas se comunican bidireccionalmente con el cerebro a través del nervio vago. En el trastorno de dolor abdominal funcional, los mecanorreceptores de bajo umbral en la pared intestinal de Valentina se han sensibilizado — se activan con volúmenes de distension mecánica que no activarían esas neuronas en una niña sin esta condición. El movimiento normal del intestino — la peristalsis, el gas, la digestión normal — activa estas neuronas sensibilizadas como si fuera una amenaza. Eso no es inflamación — es un cambio funcional en la sensibilidad del eje cerebro-intestino.” (Functional abdominal pain disorder — Rome IV criteria. It is a positive diagnosis, not a diagnosis of exclusion. Rome IV criteria are a clinical diagnostic system that exists because functional gastrointestinal disorders are real conditions with well-studied mechanisms. The mechanism in Valentina’s case is visceral hypersensitivity: the intestine has its own nervous system — researchers call it the ‘second brain’ — with approximately 500 million neurons in two networks called Auerbach’s myenteric plexus and Meissner’s submucosal plexus. Those neurons communicate bidirectionally with the brain through the vagus nerve. In functional abdominal pain disorder, the low-threshold mechanoreceptors in Valentina’s intestinal wall have become sensitized — they activate with volumes of mechanical distension that would not activate those neurons in a girl without this condition. Normal intestinal movement — peristalsis, gas, normal digestion — activates these sensitized neurons as if it were a threat. That is not inflammation — it is a functional change in the sensitivity of the brain-gut axis.)
Valentina had been drawing on a piece of paper from her mother’s purse. She looked up. “¿Mi intestino tiene neuronas?” (My intestine has neurons?)
“Quinientos millones de neuronas,” Patricia said. “Más que la médula espinal. Es una de las razones por las que tu intestino puede funcionar solo — no necesita instrucciones del cerebro para cada movimiento.” (Five hundred million neurons. More than the spinal cord. It is one of the reasons your intestine can function on its own — it does not need instructions from the brain for each movement.)
Valentina looked at her drawing — a spiral she had been making. “¿Y esas neuronas se pueden calmar?” (And can those neurons calm down?)
“Sí. El tratamiento que tiene la mejor evidencia en niños con el diagnóstico de Valentina es la hipnoterapia dirigida al intestino — un tipo de hipnoterapia específicamente diseñada para reducir la reactividad del sistema nervioso entérico. En un estudio clínico, el doctor Vlieger y colaboradores asignaron al azar a 53 niños con dolor abdominal funcional a recibir hipnoterapia dirigida al intestino o tratamiento médico estándar. A los 12 meses, el 52 por ciento de los niños del grupo de hipnoterapia habían tenido eliminación completa del dolor, comparado con el 12 por ciento del grupo de control. También vamos a empezar amitriptilina a una dosis pequeña al dormir — que a esta dosis no es un antidepresivo sino un neuromodulador del sistema nervioso entérico — y vamos a ajustar la fibra soluble para estandarizar el tránsito intestinal.” (Yes. The treatment with the best evidence in children with Valentina’s diagnosis is gut-directed hypnotherapy — a type of hypnotherapy specifically designed to reduce the reactivity of the enteric nervous system. In a clinical trial, Dr. Vlieger and colleagues randomly assigned 53 children with functional abdominal pain to receive gut-directed hypnotherapy or standard medical treatment. At 12 months, 52 percent of the children in the hypnotherapy group had complete elimination of pain, compared to 12 percent of the control group. We will also start amitriptyline at a small bedtime dose — which at this dose is not an antidepressant but a neuromodulator of the enteric nervous system — and we will adjust soluble fiber to standardize intestinal transit.)
Carmen looked at the lab summary in her hand and then at her daughter, who had drawn a large spiral on the paper, then drawn a second, smaller, calmer spiral next to it. “¿Cuánto tiempo tarda en mejorar?” (How long does it take to improve?)
“La hipnoterapia requiere seis a ocho sesiones semanales. La mayoría de los niños ven mejora en el período de tratamiento. Valentina ya sabe que sus neuronas intestinales se sensibilizaron y que existe un tratamiento específico para eso. Ese conocimiento por sí solo ayuda.” (Hypnotherapy requires six to eight weekly sessions. Most children see improvement during the treatment period. Valentina already knows that her intestinal neurons became sensitized and that there is a specific treatment for that. That knowledge alone helps.)
Valentina held up her drawing. The second spiral was smaller and tighter. “¿Así se vería cuando mejore?” (Is that what it would look like when I get better?)
“Exactamente así,” Patricia said. (Exactly like that.)