Cutaneous tuberculosis is a specific form of tuberculosis, characteristic of a differentiated clinical picture and resulting from either endo- or exogenous way of infection, immunological mechanisms and unfavourable conditions for mycobacterium development. The untypical course and symptoms of the disease may cause certain difficulties in obtaining a proper diagnosis and, in consequence, result in delayed onset of appropriate treatment. When diagnosing cutaneous tuberculosis, a broad apparatus of differential diagnostics should be applied, taking into account other diseases such as leishmaniasis, actinomycosis, leprosy or deep mycoses.
We report a case of lymph node tuberculosis and of colliquative tuberculosis of the skin, at first erroneously diagnosed as actinomycosis, complicated by multiform erythema.
In the reported case, no tuberculous bacilli were identified in bacteriological evaluations of bioptates collected from the skin changes. The final diagnosis of the disease was determined by the presence of specific granulation tissue in the last performed histopathological studies, as well as by hypersensitivity to tuberculin and the presence of mycobacterial DNA in PCR evaluation. According to the authors, in case of clinically suspected cutaneous tuberculosis, repeated (several) histopathological studies of samples from observed changes seem to be fairly justified. The results of histopathological studies should be completed by one of the methods of oligomycobacterial material evaluation, e.g. by identification of mycobacterial genetic material by means of nucleic acid amplification in the PCR method.