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Post-kala-azar dermal leishmaniasis (PKDL) is an infrequently occurring sequel to treated visceral leishmaniasis. Diagnosis, particularly in non-endemic areas, is difficult because the clinical appearances may be subtle and simulate lepromatous leprosy. The histopathology of the condition has been a neglected subject. Nodular lesions constitute one of the large variety of lesions that can be seen in PKDL. This paper describes the histopathology of such lesions in 26 patients seen over a period of approximately 8 years in a non-endemic setting. All the biopsies had strikingly similar light microscopic features with characteristic findings: a dense lymphohistiocytic infiltrate beneath an atrophic epidermis, pronounced follicular plugging, vascular hyalinization and collagen changes and negative Fite stain. These allow a definite diagnosis of PKDL even in the absence of demonstrable Leishman-Donovan (L-D) bodies.

Sarcoidosis is a multisystemic granulomatous disease of uncertain etiology. Recently, mycobacterial DNA especially Mycobacterium tuberculosis and Mycobacterium avium complex were detected in lung tissue and bronchial lavage fluid from patients with sarcoidosis by polymerase chain reaction (PCR) assays in 30% to 50% cases. Moreover, cell wall-defective form (CWDF) acid-fast bacteria have been isolated from skin lesions of patients with sarcoidosis which were later confirmed as M. avium complex by PCR assays. CWDF acid-fast bacteria were also found to grow from the blood of 95% patients with active sarcoidosis demonstrating a mycobacterial origin similar to M. tuberculosis. In view of these reports, we investigated 20 cases of cutaneous sarcoidosis using PCR/restriction enzyme pattern analysis (PCR/REPA) to detect mycobacterial DNA from paraffin-embedded skin biopsy samples. The method involves restriction enzyme analysis of nested PCR products obtained with primers encoding for the 65-KDa protein common to all mycobacteria. Using three restriction enzymes, the mycobacterial DNA from PCR product was differentiated to the species level. All the 20 cases had clinical and histologic evidence of sarcoidosis. Special stains for fungi (PAS) and mycobacteria (Fite) were negative and no foreign body was identified on polaroscopic examination in any of the cases. The cell lysates of M. tuberculosis, Mycobacterium bovis, Mycobacterium avium-intracellulare, Mycobacterium kansasii and Mycobacterium marinum from Centers for Disease Control (CDC) were used as standard control for PCR/REPA. Eight cases of foreign body granuloma, seven normal skin samples from the margin of surgical excisions and 5 cases of dermatitis were used as negative controls, and 4 cases of cutaneous tuberculosis were used as positive controls. Mycobacterial DNA was detected by PCR in 16 of the 20 cases of sarcoidosis. PCR/REPA subtyped 8 of these to M. tuberculosis complex (2 cases), M. avium-intracellulare (4 cases), M. kansasii (2 cases) while the other 8 cases were non-tuberculous mycobacteria. All four cases of cutaneous tuberculosis were positive by PCR and had a typical M. tuberculosis PCR/REPA pattern. Mycobacterial DNA was not detected in any of the negative controls. Our results demonstrated that mycobacterial DNA is present in 80% of cutaneous lesions of sarcoidosis and these mycobacteria may play a role in the pathogenesis of sarcoidosis.

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A 26-year-old Libyan woman presented with asymptomatic nodulo-ulcerative skin lesions present for 1 year. Three years prior to presentation, she had experienced a nasal discharge followed by the development of a nodule in the nasal cavity and a plaque on the hard palate. These lesions had gradually increased in size and ulcerated, resulting in perforation of the nasal septum and palate. Two years later, the patient noticed the appearance of skin lesions: a nodule on the right thumb and numerous nodulo-ulcerative lesions on the extremities. General physical examination was normal with no significant lymphadenopathy. Examination of the oral cavity revealed perforation of the distal nasal septum, with a perforated nodular plaque involving the entire palate, associated with subluxation of the upper incisors (Fig. 1a). On skin examination, multiple firm nodules and nodulo-ulcerative lesions with a central eschar and raised margins were observed. The lesions ranged in size from 0.5 to 5 cm and were distributed on the right hand and fingers, left upper arm (Fig. 1b), left calf, and right thigh. Routine laboratory investigations (liver function tests, serum calcium, electrolytes, lipid profile, urine and stool culture studies) were normal. Immunoelectrophoresis disclosed normal levels of immunoglobulins IgG, IgA, and IgM. Serologic studies for human immunodeficiency virus (HIV) and syphilis, and a tuberculin test, were all negative. A Giemsa-stained tissue smear was negative for Leishmania tropica organisms. Radiological studies disclosed a slight haziness of the maxillary sinuses with perforation of the nasal septum. A chest X-ray was normal. Histopathologic examination of biopsies taken from both the palate and from ulcerated and nonulcerated skin lesions was performed, and all showed similar findings. The biopsy of a nonulcerated skin lesion showed pseudoepitheliomatous epidermal hyperplasia with neutrophilic microabscesses (Fig. 2a). A dermal diffuse and nodular granulomatous mixed infiltrate of lymphocytes, histiocytes, giant cells, numerous eosinophils, and neutrophilic microabscesses was seen in all tissues examined. Septate hyphae were present both within giant cells and free in the dermis (Fig. 2b). The hyphae were branching at a 45 degrees angle and were positive on periodic acid-Schiff and Grocott methenamine silver stains (Fig. 2c). Fungal culture studies of material taken from an ulcerated skin lesion grew Aspergillus flavus. Blood cultures were negative for Aspergillus sp. or other microorganisms. The patient was treated with intravenous amphotericin B, but the medication was discontinued due to her intolerance to the drug. She was subsequently lost to follow-up.

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare variant of porokeratosis with characteristic histological feature of cornoid lamella involving the acrosyringium. We report a classic case of a 20-year-old male, who clinically presented to us with keratotic papules and plaque with pits, few having comedo like plugs, on right palm and sole since 1 year of age. A punch biopsy from palm was diagnostic as well as confirmatory showing cornoid lamella involving an eccrine duct which is the characteristic histopathological feature of PEODDN.

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IntroductionPapulopruritic eruption (PPE) occurs in people living with HIV in India. Understanding the risk factors associated with this disease may help decrease the prevalence of PPE.MethodsThis study was a case-control study performed at the Government Hospital of Thoracic Medicine, a tertiary care hospital in Chennai, India. Cases included HIV-positive, antiretroviral (ARV) therapy-naïve adults experiencing a pruritic skin eruption for longer than one month, with evidence of multiple papular or nodular lesions and biopsy consistent with arthropod bite. Controls included HIV-positive, ARV-naïve patients without active skin rash. Main outcome measures were CD4 cell count, histology, and environmental exposures. We performed statistical analysis using Epi Info version 3.5.1 and SPSS version 11.0 (SPSS Inc., Chicago, IL). Categorical variables such as gender, urban versus rural residence, occupation, treatment history, CD4 count, use of insect repellents, and environmental exposures were evaluated using the χ2 test (or the Fisher exact test when an expected value for a category was less than 5). The t-test was used to evaluate differences in age and the duration since HIV diagnosis. The Mann-Whitney test was used to compare non-normally distributed values such as CD4 cell count. A p-value that was less than 0.05 was considered to be statistically significant.ResultsForty-one cases and 149 control subjects were included. Subjects with PPE had significantly lower CD4 cell counts compared to controls (225.5 cells/µL vs. 425 cells/µL; p=0.0001). Sixty-six percent of cases had a CD4 cell count less than 350 cells/µL. PPE cases were less likely to use mosquito repellent techniques (odds ratio 2.81, CI = 1.45–5.45).DiscussionPPE may be an altered and exaggerated immune response to arthropod bites in HIV-positive patients. CD4 cell count is significantly lower in patients with PPE, and therefore it may be considered a qualifying clinical finding for ARV initiation in resource-poor settings. Protective measures against mosquito bites appeared to be important in preventing PPE in subjects at risk.