Allergic contact dermatitis is the consequence of an immune reaction mediated by T cells against low molecular weight chemicals known as haptens. It is a common condition that occurs in all races and age groups and affects the quality of life of those who present it. The immunological mechanism of this disease has been reviewed in recent decades with significant advance in its understanding. The metabolism and pathway of the haptens as well as the activation and mechanism of action of the cells responsible for both the immune reaction and its completion are discussed in this article. Keywords: Allergy and immunology; Dermatitis, allergic contact; Dermatitis, contact; Hypersensitivity Resumo: A dermatite de contato alérgica é consequência de uma reação imune mediada por células T contra químicos de baixo peso molecular, denominados haptenos. É uma condição frequente que ocorre em todas as raças e faixas etárias e afeta a qualidade de vida de seus portadores. O mecanismo imunológico desta doença vem sendo revisto nas últimas décadas com significativo avanço no seu entendimento. A metabolização e o caminho dos haptenos, bem como a formação e o mecanismo de ação das células responsáveis tanto pela reação quanto pelo seu término, são discutidos neste artigo. Palavras-chave: Alergia e imunologia; Hipersensibilidade; Dermatite de contato; Dermatites alérgicas de contato

Studies have shown a relationship between vitamin D and psoriasis. We compared serum levels of vitamin D of 20 psoriasis patients and 20 controls. The median vitamin D level was 22.80 ± 4.60 ng/ml; the median in the cases was 23.55 ± 7.6 ng/ml, and in controls 22.35 ± 3.10 ng/ml (p = 0.73). Only 2 cases and 4 controls had sufficient levels of vitamin D, although without statistical significance between the groups (p = 0.608). Levels were lower in women with psoriasis compared with those in male patients (20.85 ± 6.70 x 25.35 ± 2.90 ng/ml, p = 0.03), a finding that was not observed among controls.

Further investigation is necessary to achieve better sensitivity values.

If further studies confirm the data found, IL-13 could be used as an alternative or complementary test to detect chromium contact allergy whereas lymphocyte proliferation test, IFN-γ, IL-2, IL-5 and IL-12 detections may serve as additional diagnostic tests.

Follicular mucinosis, also known as alopecia mucinosa, is a cutaneous mucinosis histologically characterized by accumulation of dermal type mucin in the pilosebaceous follicle and sebaceous glands. It presents in two forms, a primary or idiopathic form and a secondary form associated with various benign or malignant processes. Among the malignant processes, the main association is with mycosis fungoides. The frequent overlap of clinical, histopathological, immunohistochemical and molecular biology characteristics makes the correct classification of these conditions difficult, therefore a long follow-up of all cases is recommended. We report the case of an adolescent with disseminated lesions and discuss the difficulty of early identification of secondary follicular mucinosis associated with cutaneous lymphoma.