[Urticaria pigmentosa: a current approach]. / Urticaria pigmentosa: un enfoque actual.

The term urticaria pigmentosa (UP) denotes a heterogeneous group of disorders characterized by abnormal growth and accumulation of mast cells (MC) in the skin. Symptoms result from MC chemical mediator's release, pathologic infiltration of neoplastic MC in tissues or both. Multiple molecular, genetic and chromosomal defects seem contribute to an autonomous growth, but somatic c-kit D816V mutation is more frequently found, especially in systemic disease. The aim of this paper is to provide a current overview for a better understanding of the symptoms associated with this disease, to describe its classification, recent advances in its pathophysiology and its treatment.

Urticária pigmentosa em lactentes: relato de um caso e revisão da literatura / Urticaria pigmentosa in infants: a case report and revision of literature

Paciente pediátrico, 6 meses, masculino, internado no Hospital Geral em Caxias do Sul. Apresentou lesões hipercrômicas maculopapulares descamativas, vermelho-acastanhadas, intensamente pruriginosas, atingindo grande parte do corpo. Recebeu anti-histamínicos e banhos de água e aveia, enquanto internado. Foi realizada biópsia de pele, que constatou quadro compatível com urticária pigmentosa (UP). A UP é a mais freqüente manifestação de mastocitose, ocorrendo na pele e caracterizando-se por lesões cutâneas com pigmentação persistente e pruriginosa. A mastocitose é caracterizada por um acúmulo local ou sistêmico de mastócitos, sendo que os sintomas, dentre os quais o principal é o prurido, resultam da liberação maciça de histamina e outros mediadores pelos mastócitos. O diagnóstico é baseado basicamente na história e apresentação clínica, com confirmação de envolvimento cutâneo por biópsia. Ainda não há tratamento definitivo e eficaz, e somente alívio sintomático pode ser atingido (AU)

Pediatric patient, 6 months old, male, admitted to General Hospital in Caxias do Sul. The patient displays hyperchromic maculopapular peeling lesions, reddish-brown, with intense itching extending over the majority of the body. The patient received anti-histamines and oat water baths while at the hospital. The results of a skin biopsy were indicative of urticaria pigmentosa (UP). UP is the most common manifestation of mastocytosis, occurring in the skin and characterized by cutaneous lesions with persistent and itching spots. Mastocytosis is characterized by a local or systemic accumulation of mast cells, accompanied by symptoms, among which the primary one is itching, resulting from the massive release of histamine and other mediators by the mast cells. Diagnosis is based basically on clinical history and examination, confirmed by cutaneous biopsy. There is still no satisfactory and efficient treatment, and only the symptoms can be alleviated (AU)

Cutaneous mastocytosis in children: a clinical analysis of 71 cases.

OBJECTIVE: To characterize the clinical features, response to therapy, evolution and prognosis of cutaneous mastocytosis in children. BACKGROUND: Mastocytosis in children, instead of being induced by a potentially oncogenic c-kit mutation, is probably a clonal disease with benign prognosis. METHODS: The clinicopathological features, evolution and response to treatment were analysed in 71 children with mastocytosis. RESULTS: There were 53 (75%) cases of urticaria pigmentosa, 12 (17%) cases of mastocytoma, and six (8%) cases of diffuse cutaneous mastocytosis. In 92% of cases disease onset was in the first year of life. There was a male predominance 1.8 : 1. Treatment did not modify the disease evolution. Eighty per cent of patients improved or had spontaneous resolution of the disease. CONCLUSION: The most frequent clinical form of mastocytosis was urticaria pigmentosa followed by mastocytoma and diffuse cutaneous mastocytosis. Darier's sign was present in 94% of cases. A negative Darier's sign does not rule out mastocytosis. In contrast to adults, mastocytosis in children usually has a benign course making sophisticated or invasive diagnostic tests unnecessary. A classification of paediatric cutaneous mastocytosis is proposed.