Coma blisters after poisoning caused by central nervous system depressants: case report including histopathological findings / Bolhas do coma pós-intoxicação por depressores do sistema nervoso central: relato de caso incluindo achados histopatológicos

Blister formation and eccrine sweat gland necrosis is a cutaneous manifestation associated with states of impaired consciousness, most frequently reported after overdoses of central nervous system depressants, particularly phenobarbital. The case of a 45-year-old woman who developed "coma blisters" at six distinct anatomic sites after confirmed (laboratory) phenobarbital poisoning, associated with other central nervous system depressants (clonazepam, promethazine, oxcarbazepine and quetiapine), is presented. A biopsy from the left thumb blister taken on day 4 revealed focal necrosis of the epidermis and necrosis of sweat gland epithelial cells; direct immunofluorescence was strongly positive for IgG in superficial blood vessel walls but negative for IgM, IgA, C3 and C1q. The patient was discharged on day 21 with no sequelae.

Formação de bolhas e necrose de glândula sudoríparas écrinas é uma manifestação cutânea associada com estados de diminuição da consciência, mais frequentemente relatada após superdosagens de depressores do sistema nervoso central, particularmente fenobabital. Relatamos o caso de uma paciente de 45 anos que desenvolveu "bolhas do coma" após tentativa de suicídio por fenobarbital (confirmada laboratorialmente), associada a outros depressores do sistema nervoso central (clonazepam, prometazina, oxcarbazepina e quetiapina). Biópsia da bolha do 1o quirodáctilo esquerdo no 4o dia de internação revelou necrose focal da epiderme e necrose de células epiteliais de glândula sudorípara; a imunofluorescência direta foi fortemente positiva para IgG na parede superficial dos vasos sanguíneos, mas negativa para IgM, IgA, C3 e C1q. A paciente teve alta no 21o dia, sem seqüelas.

Methimazole-Induced Bullous Systemic Lupus Erythematosus: A Case Report

Bullous systemic lupus erythematosus (SLE) is a kind of LE-non-specific bullous skin disease that is rarely induced by a medication. We describe the first case of bullous SLE to develop after administration of methimazole. A 31-yr-old woman presented with generalized erythematous patches, multiple bullae, arthralgia, fever, conjunctivitis, and hemolytic anemia. Biopsy of her bulla showed linear deposition of lgG, lgA, C3, fibrinogen, and C1q at dermo-epidermal junction. She was diagnosed as bullous SLE and treated with prednisolone, dapsone, hydroxychloroquine, and methotrexate. Our experience suggests that SLE should be considered as a differential diagnosis when bullous skin lesions develop in patients being treated for hyperthyroidism.

Transmission electron microscopy of the preclinical phase of experimental phytophotodermatitis

OBJECTIVE: To examine the epidermis in induced phytophotodermatitis using transmission electron microscopy in order to detect histologic changes even before lesions are visible by light microscopy. INTRODUCTION: In the first six hours after the experimental induction of phytophotodermatitis, no changes are detectable by light microscopy. Only after 24 hours can keratinocyte necrosis and epidermal vacuolization be detected histologically, and blisters form by 48 hours. METHODS: The dorsum of four adult rats (Rattus norvegicus) was manually epilated. After painting the right half of the rat with the peel juice of Tahiti lemon, they were exposed to sunlight for eight minutes under general anesthesia. The left side was used as the control and exposed to sunlight only. Biopsies were performed immediately after photoinduction and one and two hours later, and the tissue was analyzed by transmission electron microscopy. RESULTS: No histological changes were seen on the control side. Immediately after induction, vacuolization in keratinocytes was observed. After one hour, desmosomal changes were also observed in addition to vacuolization. Keratin filaments were not attached to the desmosomal plaque. Free desmosomes and membrane ruptures were also seen. At two hours after induction, similar changes were found, and granular degeneration of keratin was also observed. DISCUSSION: The interaction of sunlight and psoralens generates a photoproduct that damages keratinocyte proteins, leading to keratinocyte necrosis and blister formation. CONCLUSIONS: Transmission electron microscopy can detect vacuolization, lesions of the membrane, and desmosomes in the first two hours after experimental induction of phytophotodermatitis.