We estimate the prevalence and evaluate the clinical characteristics of leprosy related arthritis. One thousand, two hundred fifty-seven leprosy patients were attended at "Alfredo da Matta" outpatient clinic in the state of Amazonas, Brazil from July to October 2004. Among them, 115 patients were identified with articular pain and were referred for evaluation with rheumatologist. Blood samples were collected and radiological evaluation of the involved joints was performed. All patients with arthritis who continued to be followed up were reevaluated. One hundred fifteen leprosy patients (9.1%) were identified with articular involvement. The articular complaints were attributed to a defined rheumatic disease in 36 cases and excluded from further analysis. Twenty-four patients had arthralgia, and 55 (37 males and 18 females) had leprosy-related arthritis. The prevalence of arthritis was similar in both genders, and all patients with leprosy-related arthritis had lepromatous or borderline type. Most of patients had polyarticular and symmetrical arthritis and had completed the multidrug therapy and was under reaction treatment. The mean duration of articular symptoms at the time of study was 1.06 years (ranging from 5 days to 14 years). Ninety-one percent of patients with leprosy-related arthritis presented erythema nodosum leprosum or reversal reactions. Only five patients with arthritis had never presented reactions. Fifty percent of patients became asymptomatic during the mean 24 months of follow-up. Leprosy-related arthritis has a lower prevalence than previously reported. Most cases of leprosy-related arthritis were associated with reactional episodes, and in a large number of cases, the arthritis had a chronic course not responsive to the conventional therapy for reactions.

FUNDAMENTOS: A Organização Mundial da Saúde - OMS e o Ministério da Saúde do Brasil recomendam a adoção da classificação operacional para fins terapêuticos (multi ou paucibacilar). Discute-se a validade dessa classificação tomando como referência o resultado do exame baciloscópico. OBJETIVO: Verificar a sensibilidade e especificidade da classificação clínica operacional que leva em consideração exclusivamente o número de lesões cutâneas e daquela que considera o espessamento de troncos neurais, além do número de lesões cutâneas, relacionando-as com o resultado do exame baciloscópico. MÉTODO: Como fonte de informação foram consultados os prontuários de pacientes com diagnóstico de hanseníase no período de janeiro de 2000 a março de 2001, na Fundação Alfredo da Matta, em Manaus, AM, onde estavam registrados os dados demográficos, clínicos e laboratoriais. RESULTADOS: A classificação clínica baseada exclusivamente no número de lesões cutâneas mostrou sensibilidade de 73,6% e especificidade de 85,6% com relação à baciloscopia. A classificação que combina o número de lesões cutâneas e de nervos espessados demonstrou sensibilidade de 75,8% e especificidade de 71,8%. CONCLUSÃO: A classificação clínica da hanseníase baseada no número de lesões cutâneas mostrou, neste estudo, valores de sensibilidade e especificidade similares aos descritos em estudos realizados em outros países. Quando se acrescentou à classificação outro parâmetro clínico, a presença de nervos periféricos espessados, ocorreu significativa diminuição da especificidade, sem aumento estatisticamente significativo da sensibilidade.

Malignant Melanoma is a high mortality neoplasm. The involvement of the nail apparatus is rare, with only 2 out of 3 patients seeking medical attention as the result of recent nail melanocytic lesions. This results in late diagnosis and a prognosis worse than cutaneous melanoma. We report a female, presenting with ulcerative lesions with clinical and laboratory features compatible with leishmaniasis. On return after treatment initiation a longitudinal melanonychia was observed on her first right finger. Biopsy of the nail matrix was performed. Histopathology was compatible with melanoma in situ. Longitudinal melanonychia is not a specific sign for melanoma and it is important that the dermatologist should identify the suspect lesions correctly. The incidental diagnosis of nail melanoma in situ in our case significantly impacted the patient's survival.

Primary follicular mucinosis is a rare dermatosis characterized by the accumulation of mucin in the follicular epithelium and sebaceous glands. Clinically, it is characterized by the presence of papules or well-circumscribed and infiltrated plaques. In this paper, we report the case of a female patient, seven years old, evolving for three months with an asymptomatic, erythematous and infiltrated plaque located in the chin region. The research of thermal, pain and tactile sensitivity was inconclusive. Histological findings confirmed the diagnosis of follicular mucinosis. There was regression of the lesion with the use of medium potency topical corticosteroids for 20 days. The pathogenesis of follicular mucinosis remains unknown, being in some cases associated with lymphoproliferative disorders. In endemic areas of leprosy, isolated and infiltrated follicular mucinosis lesions should be further differentiated from leprosy.

Leprosy reactions are acute inflammatory processes, immunologically mediated that may be precipitated by many factors, including infections and vaccines. They are classified in Type 1 Reaction or Reversal Reaction, and Type 2 Reaction (T2LR). The most common clinical manifestation of T2LR is the erythema nodosum (EN), and, because of this, it is also called Erythema Nodosum Leprosum (ENL). Reactions can occur before, during or after the diagnosis and treatment of leprosy. We present two cases of ENL in patients who were released from treatment, and had received the first dose of ChAdOx1-S/nCoV-19 vaccine just a few days before the appearance of the skin lesions. One of them also had signs of active multibacillary leprosy. Reports of erythema nodosum related to COVID-19 disease have been published, but to our knowledge, this report is the first to describe cases of ENL related to SARS-CoV-2 vaccines.