Pityriasis Rubra Pilaris (PRP) is a chronic and rare papulosquamous disorder. Treatment of Pityriasis Rubra Pilaris is based on empiric evidence because of several doubts regarding its etiology and also because of its relative rarity, making randomized studies difficult to perform. Some factors suggest that the metabolism of vitamin A is involved in pathogenesis. We report a case of Pityriasis Rubra Pilaris associated with autoimmune hypothyroidism which presented rapid and complete response after thyroid hormone replacement, without any association with other systemic treatment. In literature there are only three other reports of significant improvement of the lesions after hormonal correction. Deficiency of thyroid hormone inhibits the conversion of carotene into vitamin A, which would be responsible for the occurrence of Pityriasis Rubra Pilaris in this patient.

CONTEXTO E OBJETIVO: O conhecimento sobre o perfil da sensibilização a alérgenos em crianças é importante para o planejamento de medidas preventivas. O objetivo deste estudo foi avaliar a prevalência e perfil de sensibilização a alérgenos inalados e alimentares em crianças e adolescentes em uma população ambulatorial na cidade de Palmas. TIPO DE ESTUDO E LOCAL: Estudo transversal em unidades ambulatoriais em Palmas, Tocantins, Brasil. MÉTODOS: Foram selecionados 94 pacientes com idades entre 1 a 15 anos em 2 ambulatórios de pediatria entre setembro e novembro de 2008. Todos os sujeitos foram submetidos a entrevistas clínicas e testes cutâneos de puntura. RESULTADOS: Um teste cutâneo de puntura positivo foi observado em 76,6% dos participantes (72,3% para inalantes, 28,9% para alérgenos alimentares). Os alérgenos mais frequentes foram Dermatophagoides pteronyssinus (34%), epitélio de gato (28,7%), epitélio de cão (21,3%), Dermatophagoides farinae (19,1%), Blomia tropicalis (18,1%), leite de vaca (9,6%) e gramíneas (9,6%). Um teste cutâneo de puntura positivo foi relacionado à história de doença atópica (razão de chances RC = 5,833, P = 0,002), história familiar de atopia (RC = 8,400, P < 0,001), asma materna (RC = 8,077, P = 0,048), exposição a animal de estimação (RC = 3,600, P = 0,012) e parto cesáreo (RC = 3,367, P = 0,019). CONCLUSÃO: Dermatophagoides pteronyssinus foi o aeroalérgeno mais prevalente e, dentre alérgenos alimentares, o leite de vaca. Houve correlação positiva entre o teste cutâneo e alguns fatores, como história familiar de atopia, asma materna, exposição a animais domésticos e parto cesáreo.

CONTEXT AND OBJECTIVE: Knowledge of the profile of allergen sensitization among children is important for planning preventive measures. The objective of this study was to assess the prevalence and profile of sensitization to inhaled allergens and food among children and adolescents in an outpatient population in the city of Palmas. DESIGN AND SETTING: Cross-sectional study at outpatient clinics in Palmas, Tocantins, Brazil. METHODS: Ninety-four patients aged 1-15 years who were attending two pediatric outpatient clinics were selected between September and November 2008. All of the subjects underwent clinical interviews and skin prick tests. RESULTS: A positive skin prick test was observed in 76.6% of the participants (72.3% for inhalants and 28.9% for food allergens). The most frequent allergens were Dermatophagoides pteronyssinus (34%), cat epithelium (28.7%), dog epithelium (21.3%), Dermatophagoides farinae (19.1%), Blomia tropicalis (18.1%), cow's milk (9.6%) and grasses (9.6%). A positive skin prick test correlated with a history of atopic disease (odds ratio, OR = 5.833; P = 0.002), a family history of atopic disease (OR = 8.400; P < 0.001), maternal asthma (OR = 8.077; P = 0.048), pet exposure (OR = 3.600; P = 0.012) and cesarean delivery (OR = 3.367; P = 0.019). CONCLUSION: Dermatophagoides pteronyssinus was the most frequent aeroallergen and cow’s milk was the most prevalent food allergen. There was a positive correlation between a positive skin prick test and several factors, such as a family history of atopic disease, maternal asthma, pet exposure and cesarean delivery.