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Vitiligo is a frequently acquired, hereditary disease, characterized by achromic macules due to the absence of melanocytes. In contrast with earlier studies, in which the main pathogenic role was attributed to anti-melanocyte antibodies, recent papers have emphasized a role for CD8 cytotoxic T lymphocytes in melanocyte destruction. Fifteen percent of peripheral T cell express cutaneous lymphocyte-associated antigen (CLA), responsible for skin-homing T cell. Phototherapy is used to treat patients with generalized vitiligo and it has been shown to interfere with CLA T cells in other skin diseases. To describe peripheral blood T cell subpopulations' frequency and ability to express the skin-homing molecule (CLA) in patients with non-segmental vitiligo, before and after photochemotherapy (PUVA). Twenty-two patients with generalized and active spreading vitiligo were submitted to 30 PUVA-8MOP sessions. Lymphocyte immunophenotyping was performed by flow cytometry using anti-CD3, anti-CD8 and anti-CLA monoclonal antibodies. Fifteen healthy volunteers, sex- and age-matched, were included as a control group. CD8-CLA T cells were significantly reduced in number in untreated vitiligo patients ( P=0.008) when compared with control individuals, albeit with a more intense CLA expression ( P=0.028). These findings were not altered after PUVA. No significant difference was noticed in CD4/CD8 ratios nor in CD4-CLA T cell numbers between vitiligo patients and controls, both before and after PUVA. CD8-CLA T cells are reduced in peripheral blood of patients with non-segmental vitiligo. This finding may be related to the previously reported increase of CD8 cells in both lesions and perilesional skin of these patients. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether photoallergic contact dermatitis is as uncommon as it is usually considered to be and to review the associated clinical features. Methods: We reviewed the literature on photoallergic reactions induced by the topical contact of the skin with a chemical in the presence of, or followed by, exposure to UV or visible light. Some of the more recently observed photo-allergens and those presenting special clinical features are discussed. Results: The literature cites several topical substances that give rise to photoallergic contact dermatitis, some of them only exceptionally but others quite frequently. The clinical features are not always those of a eczematous eruption, and several parts of the body may be affected. Conclusions: Many topical photoallergic culprits have been reported in the literature, the most important of which are sunscreen agents and, recently, non-steroidal anti-inflammatory agents (NSAIDs). Not at all exceptional is the occurrence of photoaggravation and recurrent transient or even persistent light reactions on previously exposed as well as non-exposed areas (often sparing the original application site), particularly with the NSAID ketoprofen. Moreover, cross-reactions with chemically-related as well as non-chemically related molecules are common. The potentially misleading clinical features observed in some cases, the diversity of the casual substances identified, and the low frequency with which photopatch testing is carried out in general indicate that the occurrence of photoallergic contact dermatitis might well be underestimated. [ABSTRACT FROM AUTHOR]