[Secondary cutaneous mycoses caused by Alternaria species].

Analysis of 2 of our own cases of cutaneous alternariosis (CA) and 31 reported cases showed this mycosis to be nosologically heterogeneous. CA may present as an endogenous, multilocular form or as an exogenous, usually localized form. In the endogenous form of CA (11 cases), infection most probably occurs via the lung by inhalation. The highly dermatotropic organisms spread hematogenically to the skin where they cause the typical verruciform or granulomatous lesions. In the exogenous form (8 cases), the organisms are inoculated at the site of a trauma ("traumatogenic CA"). In both forms, the underlying pathogenic disorders are of a non-mycotic nature, and hypercorticism plays the most important role. In the third form ("dermatopathic CA", 14 cases), Alternaria alternata secondarily colonizes, in a non-parasitic fashion, in preexisting lesions, which are predominantly steroid-treated eczema of the face. This form represents nosoparasitism of A. alternata rather than genuine mycosis. With regard to the pathogenesis of alternariosis, the predisposing factors mentioned are more important than the relatively weak pathogenicity of the organisms. Elimination of the predisposing factors usually cures the disease. If this fails, surgical excision of the lesions is required since an effective systemic anti-mycotic drug for CA is not yet available.