Clinical and laboratory aspects of the diagnosis and management of cutaneous and subcutaneous infections caused by rapidly growing mycobacteria.

Rapidly growing mycobacteria (RGM) are known to cause pulmonary, extra-pulmonary, systemic/disseminated, and cutaneous and subcutaneous infections. The erroneous detection of RGM that is based solely on microscopy, solid and liquid cultures, Bactec systems, and species-specific polymerase chain reaction (PCR) may produce misleading results. Thus, inappropriate therapeutic measures may be used in dermatologic settings, leading to increased numbers of skin deformity cases or recurrent infections. Molecular tools such as the sequence analyses of 16S rRNA, rpoB and hsp65 or PCR restriction enzyme analyses, and the alternate gene sequencing of the superoxide dismutase (SOD) gene, dnaJ, the 16S-23S rRNA internal transcribed spacers (ITS), secA, recA1, dnaK, and the 32-kDa protein gene have shown promising results in the detection of RGM species. PCR restriction enzyme analyses (PRA) work better than conventional methods at identifying species that are closely related. Recently introduced molecular tools such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), pyrosequencing, DNA chip technology, and Beacon probes-combined PCR probes have shown comparable results in the detection of various species of RGM. Closely related RGM species (e.g., Mycobacterium fortuitum, M. chelonae, and M. abscessus) must be clearly differentiated using accurate molecular techniques because their therapeutic responses are species-specific. Hence, this paper reviews the following aspects of RGM: (i) its sources, predisposing factors, clinical manifestations, and concomitant fungal infections; (ii) the risks of misdiagnoses in the management of RGM infections in dermatological settings; (iii) the diagnoses and outcomes of treatment responses in common and uncommon infections in immunocompromised and immunocompetent patients; (iv) conventional versus current molecular methods for the detection of RGM; (v) the basic principles of a promising MALDI-TOF MS, sampling protocol for cutaneous or subcutaneous lesions and its potential for the precise differentiation of M. fortuitum, M. chelonae, and M. abscessus; and (vi) improvements in RGM infection management as described in the recent 2011 Clinical and Laboratory Standards Institute (CLSI) guidelines, including interpretation criteria of molecular methods and antimicrobial drug panels and their break points [minimum inhibitory concentrations (MICs)], which have been highlighted for the initiation of antimicrobial therapy.

Verrucous condyloma lata mimicking condyloma acuminata: An unusual presentation.

A 15-year-old boy from a child center presented with a three-month history of a growth in the perianal region. There was a history of repeated peno-anal sexual exposures. On examination there was a fleshy, hyperpigmented, verrucous plaque around the anal verge. The Venereal Disease Research Laboratory Test was reactive in a titer of 1 : 64. Lesional biopsy showed marked epidermal hyperplasia without koilocytes, with a dermal infiltrate composed of lymphocytes, plasma cells and histiocytes. Patient was treated with parenteral penicillin with complete healing of the plaque. This is a rare presentation of secondary syphilis showing condyloma lata resembling condyloma acuminata.

A comparative clinico-pathological study of single dose ROM in paucibacillary leprosy patients with 1-3 skin lesions.

A controlled clinical and histopathological study was carried out to compare the efficacy of a combination of rifampicin 600 mg plus ofloxacin 400 mg plus minocycline 100 mg (ROM) administered as a single dose with that of standard WHO/MDT-PB six months' regimen with regard to resolution of lesion clinically and histopathologically. Skin biopsy was performed at the intake and at 6 months. The study subjects were 32 previously untreated, smear-negative patients, without nerve trunk involvement and having 1-3 skin lesions. The results were analyzed for mean clinical score for marked, moderate and no improvement and mean histopathological score was graded as active, resolving and complete resolution, according to granuloma fraction at the end of 6 months. Marked clinical improvement was seen in 25% and 12%, moderate improvement in 50% and 56% patients treated with ROM and standard regimens respectively. Histopathologically, activity was seen in 62.5% and 43.7% and resolution of granuloma in 25% and 31.2% in the ROM and standard regimens respectively. Both the regimens were equally efficacious in the reduction of clinical score and granuloma fraction. No adverse drug reactions or reversal reactions were seen during the study period in both the groups.