Dermoscopic features of basal cell carcinoma in skin of color: A retrospective cross-sectional study from Puducherry, South India.

BACKGROUND: Dermoscopy is useful in the diagnosis of basal cell carcinoma (BCC). However, most descriptions of the dermoscopic features of BCCs are in Caucasians (skin types I-III) and there is a paucity of data in dark-skinned Indian patients. AIMS: The aim of this study was to describe the various dermoscopic features of BCC in dark-skinned patients from South India and correlate these with the histopathologic subtypes. METHODS: A retrospective observational study of biopsy-proven cases of BCC was conducted at a tertiary care center in South India using nonpolarized contact dermoscopy. RESULTS: Sixty BCCs in 35 patients predominantly of skin phototypes IV or V were studied. These included 32 nodular, 27 superficial and 1 infiltrative type of BCC. The most common dermoscopic features noted were maple leaf-like areas (61.7%), blue-white veils (53.4%), ulceration (48.4%) and short fine telangiectases (46.7%). Ulceration, blue-white veils and arborizing vessels were significantly associated with nodular BCCs, while maple leaf-like areas, red-white structureless areas, multiple small erosions and spoke wheel areas were noted with superficial BCCs. LIMITATIONS: The limitations of this study include its retrospective nature, the use of only nonpolarized light for examination, the lack of other histopathological variants of BCC as well as the lack of a comparison group. CONCLUSION: We report a dermoscopic study of BCC in dark-skinned patients from Puducherry, South India. The blue-white veil was observed in half of the patients and was significantly associated with nodular BCCs. The addition of the blue-white veil to the diagnostic criteria for pigmented BCC could improve the diagnostic accuracy of dermoscopy in Indian patients.

Genetics and Genomics of the Genus Amycolatopsis.

Actinobacteria are gram-positive filamentous bacteria which contains some of the most deadly human pathogens (Mycobacterium tuberculosis, M. leprae, Corynebacterium diphtheriae, Nocardia farcinica), plant pathogens (Streptomyces scabies, Leifsonia xyli) along with organisms that produces antibiotic (Streptomycetes, Amycolatopsis, Salinospora). Interestingly, these bacteria are equipped with an extraordinary capability of producing antibiotics and other metabolites which have medicinal properties. With the advent of inexpensive genome sequencing techniques and their clinical importance, many genomes of Actinobacteria have been successfully sequenced. These days, with the constant increasing number of drug-resistant bacteria, the urgent need for discovering new antibiotics has emerged as a major scientific challenge. And, unfortunately the traditional method of screening bacterial strains for the production of antibiotics has decreased leading to a paradigm shift in the planning and execution of discovery of novel biosynthetic gene clusters via genome mining process. The entire focus has shifted to the evaluation of genetic capacity of organisms for metabolite production and activation of cryptic gene clusters. This has been made possible only due to the availability of genome sequencing and has been augmented by genomic studies and new biotechnological approaches. Through this article, we present the analysis of the genomes of species belonging to the genus Amycolatopsis, sequenced till date with a focus on completely sequenced genomes and their application for further studies.

Evaluation of role of Candida in patients with chronic paronychia.

BACKGROUND: Chronic paronychia, earlier considered to be an infection due to Candida, is currently being considered as a dermatitis of the nail fold. Irritant, allergic and protein contact dermatitis are the suggested major pathogenic mechanisms. Hypersensitivity to Candida is more likely to be the etiology, rather than the infection itself. AIMS: To assess the clinico-etiological profiles of patients with chronic paronychia and to determine the role of contact sensitization and hypersensitivity to Candida. METHODS: All consecutive patients of chronic paronychia attending the dermatology outpatient department (OPD) were assessed for risk factors, number of nails affected, clinical presentation and presence of fungus, patch tested for contact allergy and prick tested for hypersensitivity to Candida allergen. RESULTS: A total of 80 patients of chronic paronychia were recruited into our study. There was female preponderance (66 patients, 82.5%), with the most common group affected being housewives (47 patients, 58.8%). Frequent washing of hands (64 patients, 80%) was the most common risk factor. Fungal culture was positive in 56.1% (41 patients), the predominant species cultured was Candida albicans (15 patients, 36.5%). Patch testing with Indian standard series was positive in 27.1% patients (19 out of 70 patients tested), with nickel being the most common allergen. Prick test with Candida allergen was positive in 47.6% patients (31 out of 65 patients tested). LIMITATIONS: Prick test and patch test provide indirect evidence of hypersensitivity, with inherent limitations. CONCLUSION: Our study shows that chronic paronychia is probably a form of hand dermatitis associated with prolonged wet work, and that there is a higher incidence of contact sensitization and Candida hypersensitivity in these patients.

Type 1 lepra reaction in histoid leprosy.

OBJECTIVES: Lepra reaction in histoid leprosy (HL) is rare; there are few reports of type 2 lepra reaction in HL. We report a 42-year-old woman with HL in type 1 lepra reaction after 10 weeks of multibacillary multi-drug therapy (MBMDT). CASE REPORT: A 42-year-old woman presented with asymptomatic multiple papules, plaques, and nodules over the face, trunk, and extremities and no history of prior treatment with anti-leprosy drugs. A biopsy of a skin nodule on the forearm revealed spindle-shaped, non-vacuolated histiocytes in a whorled pattern with abundant acid-fast bacilli (AFB). The patient was diagnosed with HL and started on MBMDT. Ten weeks later, she developed pruritic, painful, erythematous, and edematous papules, plaques, and nodules over the face, trunk, and extremities, without constitutional symptoms. Histopathology revealed an atrophic epidermis, preserved grenz zone, and papillary dermal edema. Elongated AFB were visible on Fite's stain. The MBMDT was continued, along with nonsteroidal anti-inflammatory drugs and antihistamines, but pruritus, pain, erythema, and edema persisted, and new skin lesions appeared. The patient was started on prednisolone at 0.75 mg/kg body weight/day. Prednisolone resulted in symptomatic relief and the healing of ulcerated papules within four weeks. Treatment was tapered and stopped after 20 weeks. CONCLUSIONS: Histoid leprosy is considered a variant of lepromatous leprosy, which rarely involves a lepra reaction. Pruritus and ulceration of skin lesions as manifestations of type 1 lepra reaction in HL have not been reported previously. These symptoms manifested after 10 weeks of MBMDT and responded well to oral prednisolone.

Modification of rifamycin polyketide backbone leads to improved drug activity against rifampicin-resistant Mycobacterium tuberculosis.

Rifamycin B, a product of Amycolatopsis mediterranei S699, is the precursor of clinically used antibiotics that are effective against tuberculosis, leprosy, and AIDS-related mycobacterial infections. However, prolonged usage of these antibiotics has resulted in the emergence of rifamycin-resistant strains of Mycobacterium tuberculosis. As part of our effort to generate better analogs of rifamycin, we substituted the acyltransferase domain of module 6 of rifamycin polyketide synthase with that of module 2 of rapamycin polyketide synthase. The resulting mutants (rifAT6::rapAT2) of A. mediterranei S699 produced new rifamycin analogs, 24-desmethylrifamycin B and 24-desmethylrifamycin SV, which contained modification in the polyketide backbone. 24-Desmethylrifamycin B was then converted to 24-desmethylrifamycin S, whose structure was confirmed by MS, NMR, and X-ray crystallography. Subsequently, 24-desmethylrifamycin S was converted to 24-desmethylrifampicin, which showed excellent antibacterial activity against several rifampicin-resistant M. tuberculosis strains.

Novel presentation of lepromatous leprosy in an erythema gyratum repens-like pattern.

OBJECTIVES: Leprosy can have diverse cutaneous and occasionally perplexing presentations. We report an unusual case of lepromatous leprosy (LL) with annular lesions resembling erythema gyratum repens. REPORT: A 55-year-old man presented with a symmetrical, hypopigmented, and erythematous rash of bizarre appearance over the lateral aspect of the upper arm, and anterior and posterior aspects of the trunk of two months' duration. He gave a history of self-resolving episodes of bilateral pedal edema, and numbness and pricking sensations in both the hands and feet, which had occurred intermittently over the previous six years. An ulcer measuring 2 cm in size was present over the adjacent surface of the right first and second toes. The bilateral ulnar and radial cutaneous nerves were symmetrically thickened. RESULTS: Slit-skin smears revealed numerous acid-fast bacilli. Skin biopsy from the trunk showed collections of histiocytes, lymphocytes, and plasma cells in the dermis and around the blood vessels. The patient was diagnosed with LL and started on multibacillary multi-drug therapy. CONCLUSIONS: Lepromatous leprosy can have varied clinical manifestations and is often a great imitator. However, the skin smear positivity, even in normal skin, symmetrical cutaneous and peripheral nerve involvement, and histopathology in the present patient were indicative of LL. This report highlights a rare presentation of leprosy. Clinicians should be aware of these rare manifestations as lepromatous cases still occur in certain regions.

Is it Lucio Phenomenon or Necrotic Erythema Nodosum Leprosum?

Lucio phenomenon (LP) or erythema necroticans is a relatively rare, peculiar reaction pattern occurring in untreated lepromatous (LL) or borderline lepromatous (BL) leprosy cases. A 38-year-old male, a cook by occupation, was referred to the dermatology clinic from otolaryngology department with blistering over both the hands and feet of 2 days duration. He had been admitted 1 week back with epistaxis and nasopharyngeal myiasis in otolaryngology department. He was started on systemic antibiotics gentamycin, crystalline penicillin, and metronidazole with nasal instillation of turpentine oil 2 drops 6 times a day. Two days later, he had developed edema with painless hemorrhagic blistering over the dorsum of left hand followed by involvement of the right hand, dorsa of both feet, and both the earlobes within a day. Histopathology of the blister showed sub-epidermal blister, with necrotizing leukocytoclastic vasculitis of papillary dermal vessels with thrombosis, numerous acid-fast bacilli in macrophages, and macrophage granulomas extending up to subcutis. In view of the absent fever or constitutional symptoms, and the classical angular infarcts and hemorrhagic blisters evolving into ulcers with angulated margins, we considered LP as the most likely diagnosis. The patient was started on a combination of WHO recommended multibacillary anti-leprosy therapy and prednisolone (40 mg/day).