[Allopurinol hypersensitivity syndrome. A report of two cases]. / Síndrome de hipersensibilidad por alopurinol. Informe de dos casos clínicos.

Patients in treatment with allopurinol are in risk of having life threatening adverse reactions particularly at the beginning of the treatment. Two percent of the patients prescribed with this drug have associated severe cutaneous adverse reactions. We present two cases of allopurinol hypersensitivity syndrome in mexican patients in which asymptomatic hyperuricemia was the indication to its use. The general physician and the specialist must be alert of this syndrome that causes elevate morbidity and mortality.

Los pacientes bajo tratamiento con alopurinol pueden presentar reacciones adversas potencialmente mortales, particularmente al inicio del tratamiento. Las reacciones cutáneas adversas por alopurinol tienen una prevalencia aproximada del 2 %. Presentamos dos casos de síndrome de hipersensibilidad por alopurinol en pacientes mexicanos en quienes la hiperuricemia asintomática fue la indicación para su uso. El médico general y el especialista deben estar alerta ante este síndrome que ocasiona alta morbilidad y mortalidad.

CD4, IL-17, and COX-2 Are Associated With Subclinical Inflammation in Malar Melasma.

The pathogenesis of melasma, a common, photo-induced hyperpigmentary disorder, is not clearly understood. Significant factors linked to melasma are ultraviolet radiation exposure and genetic predisposition. Histological analysis has demonstrated that melasma is caused by a network of cellular interactions among melanocytes, keratinocytes, mast cells, fibroblasts, and dermal vasculature exhibits, features similar to chronic sun damage. Dermal inflammation caused by ultraviolet radiation might play an important role in the hyperpigmentation and reactivation of melasma lesions through the production of melanogenic cytokines and growth factors. Because the role of inflammation in this disorder is unknown, we used histochemistry, immunohistochemistry, and quantitative real-time polymerase chain reaction to evaluate melasma lesions from healthy female patients (n = 20) with malar melasma. Lesional skin without specific solar exposure or photoprotection measures within the previous 4 weeks was compared with nonlesional skin. The increased lymphocytic infiltrate in lesional skin was mainly composed of CD4 T cells, mast cells, and macrophages. Levels of the cytokine interleukin (IL)-17 and the proinflammatory mediator cyclooxygenase (COX)-2 were significantly elevated in affected skin compared with healthy skin. In addition, the Melasma Activity and Severity Index score, fraction of solar elastosis, and epidermal melanin were positively associated with COX-2 expression. There was no statistically significant difference in IL-1α, IL-1ß, R-IL1, IL-6, IL-8, vascular endothelial growth factor, and tumor necrosis factor alpha expression levels. Together, these data indicated that melasma under unchallenged conditions is characterized by chronic inflammatory cells and mediators, which may explain its recurrent nature.

Hyperpigmentation and atrophy in folds as cutaneous manifestation in a case of mitochondrial myopathy.

Mitochondrial myopathies are inborn metabolism defect diseases manifested by symptoms reflecting failure of the final step in the mitochondrial respiratory chain. Clinical expression of these conditions can vary widely, but typically includes organ systems with a high energy demand, such as striated muscle, myocardium, and nervous and liver tissues. In contrast, cutaneous manifestations are rare and are non-specific, most commonly presenting as pigmentation disorders. In this case report, we present a case of Alpers syndrome accompanied by hyperpigmentation and atrophy in skin folds.