No abstract

The incidence of infections caused by non-tuberculous mycobacteria has increased in recent years, due to a rise in dermatological procedures and a greater prevalence of immunosuppression in the general population. This study investigated the clinical and microbiological findings of non-tuberculous mycobacterial skin infections. The study population included 29 patients from whom non-tuberculous mycobacteria were cultured after isolation from skin biopsy materials, cutaneous abscesses or exudates. Clinical, microbiological and epidemiological data were collected from each patient. Eight patients were immunocompromised while 21 were not. Precipitating factors such as acupuncture, filler injection, surgical procedures and other traumatic events preceded infection in 13 (including 11 normal hosts and two immunocompromised hosts) of the 29 patients. Multiple skin lesions were present in eight patients (including three normal hosts and five immunocompromised hosts). In eight patients (including four immunocompromised hosts), symptoms were accompanied by tenosynovitis, osteomyelitis and myositis. Mycobacterium abscessus was isolated from nine patients, Mycobacterium fortuitum was isolated from nine patients, Mycobacterium chelonae was isolated from six patients, Mycobacterium marinum was isolated from two patients, a Mycobacterium avium complex member was isolated from two patients, and Mycobacterium haemophilum was isolated from one patient. Ten of the 24 cases caused by rapidly growing organisms (i.e. M. chelonae, M. abscessus and M. fortuitum groups) were precipitated by skin injuries such as acupuncture, filler infection and other medical procedures. Increases in skin medical procedures, including both acupuncture and esthetic interventions, explain the increasing incidence of these organisms. Immunocompromised patients tended to develop multiple skin lesions and deep tissue infections.

Prurigo pigmentosa is a recurrent dermatosis with severe pruritus and several peculiar clinical features. Its exact etiology and pathogenesis are unclear. The aim of this study was to investigate the clinical features and chronological changes in the histopathology of prurigo pigmentosa in Korean patients and to assess the etiology of this condition. We reviewed the medical records, clinical photographs and biopsy specimens from 50 patients diagnosed with prurigo pigmentosa. Mean age at diagnosis was 23.7 years (range, 15-61 years). Prurigo pigmentosa started as urticarial papules or plaques, changing first to papulovesicles and then to reticulated brownish macules. The most frequent sites were the back and chest, especially depressed areas such as the central back and inter-mammary area. Dietary change was suspected as a cause of prurigo pigmentosa in 17 patients. Histopathologically, early-stage lesions had dermatitis herpetiformis-like features; fully-developed lesions displayed impetigo-like or acute, generalized, exanthematous, pustulosis-like features; and late lesions presented with post-inflammatory hyperpigmentation-like features. Oral minocycline, with or without dapsone, was effective in inhibiting the appearance of new lesions, but did not prevent recurrence. Prurigo pigmentosa is not rare in Korea, is apparently associated with dietary modification and preferentially involves the depressed regions of the trunk.