Mastocitosis cutánea: reporte de un caso / Cutaneous mastocytosis: A case report

Introducción La mastocitosis representa un grupo de enfermedades caracterizadas por una acumulación excesiva de mastocitos en uno o múltiples tejidos. Puede limitarse a la piel o tener un compromiso sistémico, siendo de baja prevalencia y pronóstico benigno en la infancia. Objetivo Reportar un caso de urticaria pigmentosa como subtipo de mastocitosis cutánea y hacer una revisión bibliográfica enfocada en los hallazgos clínicos, el diagnóstico y el manejo inicial básico. Caso clínico Lactante de 6 meses de edad con múltiples máculas y pápulas de color café claro localizadas en el tronco, los brazos y las piernas, cuadro compatible con una urticaria pigmentosa, confirmada mediante biopsia. Se solicitaron exámenes para descartar compromiso sistémico. La paciente fue tratada con medidas generales, educación y antihistamínicos, con excelente evolución. Conclusiones La mastocitosis cutánea es una enfermedad poco común, de buen pronóstico. En la infancia generalmente bastan las medidas generales y educación para obtener resultados favorables. La terapia farmacológica de primera línea son los antagonistas H1.

Introduction Mastocytosis represents a group of diseases characterised by an excesive accumulation of mastocytes in one or multiple tissues. It can affect only the skin, or have a systemic involvement. It has a low prevalence, and the prognosis is benign in children. Objective To report a case of urticaria pigmentosa as a subtype of cutaneous mastocytosis, and present a literature review focused on clinical findings, diagnosis and initial basic management. Clinical case A child of six months of age presenting with multiple blemishes and light brown papules located on the trunk, arms and legs. The symptoms were compatible with urticaria pigmentosa, and was confirmed by biopsy. Tests to rule out systemic involvement were requested. The patient was treated with general measures, education, and antihistamines, with favourable results. Conclusions Cutaneous mastocytosis is a rare disease with a good prognosis. In childhood general measures and education are usually enough to obtain favourable results. Histamine H1 antagonists are the first line drug treatment.

Histamina, receptores de histamina e anti-histamínicos: novos conceitos / Histamine, histamine receptors and antihistamines: new concepts

As drogas com ação anti-histamínica estão entre as medicações mais comumente prescritas na prática dermatológica diária, tanto em adultos como em crianças. Este artigo aborda os novos conceitos da função dos receptores de histamina (receptores H1) e discute os efeitos anti-inflamatórios dessas drogas. A segunda geração de anti-histamínicos difere da primeira geração devido a sua elevada especificidade e afinidade pelos receptores H1 periféricos e devido a seu menor efeito no sistema nervoso central, tendo como resultado menores efeitos sedativos. Embora a eficácia dos diferentes anti-histamínicos H1 (anti-H1) no tratamento de doentes alérgicos seja similar, mesmo quando se comparam anti-H1 de primeira e de segunda geração, eles são muito diferentes em termos de estrutura química, farmacologia e propriedades tóxicas. Consequentemente o conhecimento de suas características farmacocinéticas e farmacodinâmicas é importante para a melhor prática médica, especialmente em gestantes, crianças, idosos e doentes com comorbidades.

Drugs with antihistamine action are the most commonly prescribed medication in daily dermatologic practice, both to adults and children. This article addresses new concepts of the role of histamine receptors (H1 receptors) and discusses the anti-inflammatory effects of these drugs. Second generation antihistamines differs from first generation because of their high specificity and affinity for peripheral H1-receptors. Second generation antihistamines are also less likely to produce sedation because they have less effect on the central nervous system. Although the efficacy of the various H1-antihistamines in the treatment of allergic patients is similar, even when comparing first- and second-generation drugs, these drugs are still very different in terms of their chemical structure, pharmacology and toxic properties. Consequently, knowledge of their pharmacokinetic and pharmacodynamic characteristics is essential for a better medical care, especially that offered to pregnant women, children, the elderly, and patients with comorbidities.