Erythema induratum of Bazin presenting as peripheral neuropathy.

Erythema induratum of Bazin (EIB) is a rare tuberculid that typically affects middle-aged women. We report a unique case of EIB in a 57-year-old Hispanic woman who presented with recurrent painful plaques and nodules on the lower extremities, specifically on the pretibial area of the legs and dorsal aspect of the feet, with a severe burning sensation on the feet that resolved after antituberculosis therapy. We review the characteristics of EIB and examine how the unique presentation of peripheral neuropathy may relate to the pathophysiology of this disease.

Outbreak of nontuberculous mycobacterial disease in the central Pacific.

Approximately 10% of the island population of Satowan (population, 650 persons), a small, remote coral island in the central Pacific, suffers from an acquired, chronic, disfiguring skin condition known locally as "spam." This skin disease has affected the island population since shortly after World War II. An investigation in 2007 revealed that this skin disease is caused by a nontuberculous mycobacterial infection closely related to Mycobacterium marinum. This article reviews the fascinating history of this skin disease on Satowan, its distinctive clinical presentation, and recommendations for diagnosis and treatment of clinically similar skin lesions in Pacific Islanders.

Disseminated dermal Trichophyton rubrum infection - an expression of dermatophyte dimorphism?

We present a case of disseminated dermal infection caused by Trichophyton rubrum (T. rubrum). This rare variant of dermatophytosis has an atypical clinical and histopathological presentation and occurs exclusively in immunosuppressed patients. The large, broad, pleomorphic hyphae with scattered budding arthrospores in this variant of T. rubrum infection are unusual and may represent expression of dermatophyte dimorphism previously described in vitro.

Sequelae of World War II: an outbreak of chronic cutaneous nontuberculous mycobacterial infection among Satowanese islanders.

BACKGROUND: After World War II, residents of Satowan (population, 650 persons), an outer island in the state of Chuuk, Federated States of Micronesia, noted a high prevalence of a chronic, progressive skin disease known locally as "spam." METHODS: Island residents who had chronic, progressive verrucous or keloidal plaques for >3 months were considered case patients. Tissue specimens were obtained for culture, histopathological analysis, mycobacterial polymerase chain reaction (PCR), and comparison with the hsp65 gene of Mycobacterium marinum. We performed a case-control study involving all cases and randomly selected control individuals from the community. RESULTS: A total of 39 case patients were identified, with a median age of 26.0 years (range, 8-82 years); 74.4% were male, and the mean duration of disease was 12.5 years. A total of 98 control individuals were enrolled. Results of all 19 mycobacterial tissue cultures were negative, and histopathological analysis of all 9 lesions showed suppurative granulomatous inflammation with negative results of mycobacterial and fungal stains. In 7 of 9 paraffin-embedded samples, nontuberculous mycobacterial DNA was detected by PCR, and 2 sequenced products had 95% and 87% identity to M. marinum. All case patients were taro farmers (odds ratio, undefined; P < .01), and among taro farmers, when the analysis was controlled for sex, contact with water-filled World War II-era bomb craters was associated with infection (odds ratio, 8.2; P < .01). CONCLUSIONS: "Spam disease" is a chronic, progressive skin disease of high prevalence on Satowan and is associated with taro farming and contact with World War II-era bomb craters. Histopathological and PCR data demonstrate a nontuberculous mycobacterial infection as the cause.

Th17 cytokines stimulate CCL20 expression in keratinocytes in vitro and in vivo: implications for psoriasis pathogenesis.

T helper (Th) 17 cells have recently been implicated in psoriasis pathogenesis, but mechanisms of how these cells traffic into inflamed skin are unknown. By immunostaining for interleukin (IL)-17A and IL-22, we show numerous cells present in psoriasis lesions that produce these cytokines. We next found that Th17 cytokines (IL-17A, IL-22, and tumor necrosis factor (TNF)-alpha) markedly increased the expression of CC chemokine ligand (CCL) 20, a CC chemokine receptor (CCR)6 ligand, in human keratinocyte monolayer and raft cultures in a dose- and time-dependent manner. Lastly, we showed in mice that subcutaneous injection with recombinant IL-17A, IL-22, or TNF-alpha led to the upregulation of both CCL20 and CCR6 expression in skin as well as cutaneous T-cell infiltration. Taken together, these data show that Th17 cytokines stimulate CCL20 production in vitro and in vivo, and thus provide a potential explanation of how CCR6-positive Th17 cells maintain their continual presence in psoriasis through a positive chemotactic feedback loop.

Mycobacterium marinum presenting as large verrucous plaques on the lower extremity of a South Pacific Islander.

Mycobacterium marinum is an environmental, nontuberculous mycobacteria found in fresh and salt water, causing disease in humans through traumatized skin. We describe a young, healthy South Pacific Islander with chronic, progressive large verrucous plaques on the left lower extremity, with cultures positive for M. marinum. This morphology, distribution, and disease course is likely representative of an atypical presentation of M. marinum infection in South Pacific Islanders.