Proctocolite induzida por proteína alimentar - teste de provocação oral deve ser realizado para confirmar o diagnóstico de alergia ao leite de vaca em neonatos? / Induced proctocolitis - oral food challenge should be done to confirm the diagnosis of cow's milk allergy in neonates?

ABSTRACT Background: Suspicion of food protein-induced proctocolitis based on empirical understanding of rectal bleeding can lead to misdiagnosis. Objective: to verify clinical and evaluative characteristics of patients who presented neonatal rectal bleeding and were on a restricted cow's milk diet. Methods: A cross-sectional retrospective study included patients followed up in a tertiary care center, who presented rectal bleeding in the neonatal period. The analyzed data included gender, gestational age, type of delivery, use of antibiotics during the last trimester of pregnancy, use of parenteral nutrition before the first manifestation, use of mechanical ventilation, initial clinical manifestations associated with rectal bleeding, diet before the first manifestation, period of elimination diet, oral food challenge (OFC) results and symptoms presented in cases of positive OFC. Fisher's exact test and Mann-Whitney test were used to analyze the data. The level of significance was set to 5%. Results: Forty-two patients were selected: 30 preterm infants, 34 cesarean deliveries, 10 exclusively breastfed patients before rectal bleeding. Median age at OFC was 6.3 months old. Median of length of the elimination period before OFC was 5.9 months. OFC was negative in 33/42 (79%) patients and positive in 9/42 (21%). There was no association between OFC results and the evaluated data. The main symptom observed in patients with positive OFC was blood in stools. Conclusion: OFC was negative in most cases of suspected cow's milk allergy due to rectal bleeding in neonates, most of them with a history of prematurity.

RESUMO Contexto: A suspeita de proctocolite induzida por proteína alimentar (PCIPA) com base na compreensão empírica de sangramento retal pode levar a diagnósticos equivocados. Objetivo Verificar as características clínicas e evolutivas de pacientes que apresentavam sangramento retal neonatal e faziam uso de dieta restrita com leite de vaca. Métodos: Estudo transversal retrospectivo com pacientes acompanhados em um centro terciário, que apresentaram sangramento retal no período neonatal. Os dados analisados incluíram: sexo, idade gestacional, tipo de parto, uso de antibióticos no último trimestre da gravidez, uso de nutrição parenteral antes da primeira manifestação, uso de ventilação mecânica, manifestações clínicas iniciais associadas ao sangramento retal, dieta antes da primeira manifestação, período de dieta de eliminação, resultados do teste de provocação oral (TPO) e sintomas apresentados em casos de TPO positivo. O teste exato de Fisher e o teste de Mann-Whitney foram usados para analisar os dados. O nível de significância adotado foi de 5%. Resultados: Quarenta e dois pacientes foram selecionados: 30 prematuros, 34 partos cesáreos, 10 pacientes amamentadas exclusivamente antes do sangramento retal. A idade média na ocasião do TPO foi de 6,3 meses. A mediana da duração do período da dieta de eliminação antes do TPO foi de 5,9 meses. O TPO foi negativo em 33/42 (79%) pacientes e positivo em 9/42 (21%). Não houve associação entre os resultados do TPO e os dados avaliados. O principal sintoma observado em pacientes com TPO positivo foi sangue nas fezes. Conclusão: O TPO foi negativo na maioria dos casos de suspeita de alergia ao leite de vaca devido a sangramento retal em neonatos, a maioria deles com história de prematuridade.

Estudio de validez diagnóstica de la prueba de hemorragia oculta fecal en lactantes con proctocolitis alérgica inducida por proteína alimentaria / Diagnostic validity of fecal occult blood test in infants with food protein-induced allergic proctocolitis

Resumen: Introducción: La proctocolitis alérgica inducida por proteína alimentaria (PCA) es la forma más fre cuente de alergia alimentaria no mediada por IgE. El diagnóstico se realiza por prueba de provocación oral, sin embargo, no existe una prueba diagnóstica no invasiva para su diagnóstico. Frecuentemente en Chile se utiliza la prueba de hemorragia oculta fecal (PHOF) para confirmar PCA, pero no hay estudios que respalden su indicación. Objetivo: Determinar la validez diagnóstica de la PHOF en la evaluación de lactantes con PCA. Pacientes y Método: Estudio de casos y controles con recluta miento prospectivo de lactantes con rectorragia y sospecha de PCA y lactantes sanos, en quienes se realizó una PHOF. Se indicó dieta de exclusión a los casos y luego se confirmó diagnóstico de PCA mediante contraprueba. Resultados: Se incluyó a 25 casos y 29 controles sin diferencias signi ficativas en edad, sexo, tipo de parto, alimentación o edad materna. Los casos presentaron con mayor frecuencia comorbilidades alérgicas, uso de medicamentos y antecedentes familiares de alergia. La PHOF fue positiva en 84% de casos y en 34% de controles (p<0,001). La sensibilidad de la PHOF para diagnosticar PCA fue 84%, especificidad 66%, valor predictivo positivo 68% y valor predictivo nega tivo 83%. El área bajo la curva ROC fue de 0,75 (IC 95% 0,61-0,88). Conclusiones: Si bien la PHOF tiene sensibilidad adecuada para detectar PCA en lactantes con rectorragia, resulta alterada en más de un tercio de lactantes sanos por lo que no se recomienda su uso habitual para el diagnóstico de PCA.

Abstract: Introduction: Food protein-induced allergic proctocolitis (FPIAP) is the most frequent presenta tion of non-IgE mediated food allergy (FA). The diagnosis is made by oral food challenge, however, non-invasive diagnostic tests are not available. In Chile, the fecal occult blood test (FOBT) is fre quently used to confirm FPIAP, however, there are no studies that support this practice. Objective: To establish the diagnostic validity of FOBT in the evaluation of infants with FPIAP. Patients and Method: Case-control study with prospective recruitment of infants with rectal bleeding and suspicion of FPIAP, and controls were healthy infants, in whom the FOBT was conducted. All cases underwent an elimination diet, after which the diagnosis of FPIAP was confirmed by oral food cha llenge. Results: 25 cases and 29 controls were included without significant differences in age, gen der, type of delivery, feeding, and maternal age. The cases had higher rates of allergic comorbidities, medication use, and family history of allergy. The FOBT was positive in 84% of cases and in 34% of controls (p < 0.001). The sensitivity of the FOBT for the diagnosis of FPIAP was 84%, specificity was 66%, positive predictive value 68%, and the negative predictive value 83%. The area under the ROC curve was 0.75 (CI 95% 0.61-0.88). Conclusions: Although the FOBT has an adequate sensitivity to diagnose FPIAP in infants with rectal bleeding, this test had abnormal results in more than a third of healthy infants. Therefore, the routine use of FOBT is not recommended for the diagnosis of FPIAP.

Características clínicas y manejo de lactantes menores de 1 año con sospecha de alergia a proteína de leche de vaca / Clinical characteristics and management of infants less than 1-year-old suspected with allergy to cow's milk protein

Introducción: La alergia a proteína de leche de vaca (APLV) es frecuente en lactantes (2-5% en < 1 año). Tiene múltiples formas de presentación y un amplio diagnóstico diferencial, por lo que es relevante confirmar el diagnóstico. El estándar de oro del diagnóstico es el test de provocación oral (TPO), que en la práctica no siempre se realiza. En Chile hay escasa literatura respecto a esta entidad. Objetivo: Describir características demográficas, clínicas y manejo de lactantes < 1 año con sospecha de APLV. Pacientes y Método: Estudio retrospectivo en menores de 1 año atendidos por sospecha de APLV entre 2009-2011. Se registraron datos demográficos, historia perinatal, antecedentes de atopia, alimentación al momento del diagnóstico, síntomas de sospecha de APLV, estudios realizados para su confirmación, y respuesta a tratamiento. Se consideró como estándar de diagnóstico la respuesta a la dieta y la contraprueba. Se definió como respuesta a la dieta la ausencia de los síntomas atribuidos a la APLV al menos 4 semanas desde el cambio de leche. Se realizó estadística descriptiva mediante programa Epiinfo™. Resultados: Se incluyeron 106 lactantes, 51% varones, 80% recién nacidos de término, 74% con al menos un progenitor atópico, 34% con alguno de los padres o algún hermano con alergia alimentaria. La mediana de edad al inicio fue 1,5 meses (rango: 1,5-2 m). El 15% recibió fórmula desde el período neonatal y el 50% antes del tercer mes. Los síntomas más frecuentes fueron: vómitos (63%), cólicos (50%) y rectorragia (40%); el 61% presentó ≥ 2 síntomas al comienzo. Solo en el 34% se hizo TPO, en el resto se evaluó la respuesta a la dieta de exclusión y se realizaron exámenes. La realización de exámenes no cambió la conducta. Tratamiento: 43% lactancia materna con dieta de exclusión, 24% solo fórmula extensamente hidrolizada, 26% solo fórmula aminoacídica y 7% otros. Conclusión: Las características demográficas y antecedentes de los pacientes concuerdan con lo descrito en la literatura extranjera. El inicio clínico fue precoz, predominando los síntomas digestivos. Se realizaron exámenes en una proporción alta de pacientes, sin contribuir a un cambio de conducta; el TPO fue subutilizado como herramienta diagnóstica.

Introduction: Cow's milk protein allergy (CMPA) is highly prevalent in infants (2-5%). It has a wide clinical spectrum, and confirmation through an oral food challenge (OFC) is relevant for its differential diagnosis. Information on this topic is scarce in Chile. Objective: To describe the demographic and clinical features of infants with suspected CMPA. Patients and Method: A retrospective study of patients < 1 year-old, treated for suspected CMPA between 2009 and 2011. Demographic data, symptoms of atopy, nutrition at the time of diagnosis, CMPA symptoms, diagnostic studies, and response to treatment were recorded. Diet response at least 4 weeks after milk modification, and clinical behavior when suspected foods were added back to the diet were considered standard diagnostic criteria. Descriptive statistics were performed using Epiinfo ™ software. Results: The study included 106 infants, of whom, 51% male, 80% term newborns, 74% with ≥ 1 atopic parent, and 34% with ≥ 1 parent/sibling with food allergy. The median age at onset of symptoms was 1.5 months (range 1.5-2 m). Almost half (46%) were breast-feeding ≥ 6 m, with 15% receiving formula milk since the neonatal period, and 49% before the third month. Common symptoms were: vomiting (63%), colic (49%), and bleeding on passing stools (41%). No anaphylaxis was identified, and 61% had ≥ 2 symptoms at debut. Only 34% were subjected to OFC. The most frequently requested tests were, test patch (43%), prick test (40%), and blood in stools (37%). Treatment: 43% breast feeding with exclusion diet, 24% extensively hydrolysed formula, 26% amino acid formula, and 7% others. Conclusion: Demographic characteristics and risk factors were similar to those previously described in international literature. Clinical presentation was early in life, and digestive symptoms predominated. OFC was underused for diagnosis, and most of the tests requested did not change management.

A study on the clinical courses, sigmoidoscopic and histologic findings of allergic proctocolitis / 소아과

PURPOSE: Allergic proctocolitis is a major cause of bloody stool in early infancy. This study was aimed at ascertaining the clinical courses, sigmoidoscopic and histologic findings of allergic proctocolitis. We also analyzed the relationship between peripheral eosinophilia, the age at symptom onset, and sigmoidoscopic and histologic findings. METHODS: We reviewed 25 infants retrospectively who had sigmoidoscopy and biopsy performed with a clinical diagnosis of allergic proctocolitis from April 2003 to April 2007. RESULTS: The mean age at symptom onset was 15.2+/-13.2 weeks. Fourteen infants (56.0%) were breast fed, one (4.0%) was formula fed, six (24.0%) were on combined formula, and four (16.0%) were on a weaning diet. Peripheral eosinophilia (> or =250/mm3) was seen in eighteen infants (75.0%), but total serum IgE was increased only in six (24.0%). Sigmoidoscopic findings were variable from normal (8.0%), erythema or edema (20.0%), lymphoid hyperplasia (8.0%), erosion (12.0%), hemorrhage and ulcer (4.0%) to lymphoid hyperplasia with erosion, hemorrhage, or ulcer (48.0%). Histologic findings showed focal infiltration of eosinophils in lamina propria (96.0%) and crypt epithelium (96.0%). In twenty four infants (96.0%), the number of eosinophils in mucosa was increased by a more than 60/10 high power field. There was a negative correlation between peripheral eosinophilia and the age at symptom onset. Among the twelve breast fed infants, bloody stool disappeared in ten (83.0%) with a maternal elimination diet of major food groups, but two improved spontaneously. CONCLUSION: Allergic proctocolitis should be considered as one of the major causes of bloody stool in healthy appearing infants. To confirm the diagnosis it is necessary to perform sigmoidoscopy and biopsy but histologic findings are more informative than sigmoidoscopic findings. Peripheral eosinophilia was prominent in the infants with an early onset of symptoms. Most infants experienced benign courses and recovered with the elimination of causative foods but did not need exclusive food restrictions.