A 52-year-old obese (100 kg, 1.80 m) Caucasian man presented in January 2017 with multiple nodules with purulent drainage on the upper extremities persisting for more than 10 years. Several attempts of treatment with oral antibiotics had been unsuccessful. The number of nodules was increasing over the time. He had a medical history of chronic inflammatory demyelinating polyneuropathy diagnosed in 2000. Therefore, he was on immunosuppressive therapy with methylprednisolone 20 mg per day and azathioprine 200 mg per day.
Additionally, he was on medication with acetylsalicylic acid after a myocardial infarction in 2010 and antihypertensives. Physical examination showed a violaceous firm nodule with purulent drainage over the proximal phalanx of the left middle finger (Figure 1A) and up to 20 reddish to violaceous firm nodules up to 4 x 2 cm in size on the right arm (Figure 1B). Additionally, there were extensive well-demarcated, erythematous macules with scaly borders on the chest. All finger- and toenails showed onychodystrophy and yellowish discoloration. Furthermore, physical examination revealed an enlarged lymph node in the left axilla. Abdominal ultrasound revealed a slight hepato- and splenomegaly. Biochemical examination showed an elevated white blood cell count (16.300 /mul) with relative lymphocytopenia, low hemoglobin (9.9 g/dl) with iron deficiency and elevated HbA1c (7.9%). Other routine laboratory tests were unremarkable. Screening for human immunodeficiency virus and tuberculosis was negative. Direct microscope examination by potassium hydroxide (KOH) preparation of scales from a lesion of the chest, of nail scrapings and of pyogenic fluid of a nodule showed each branched septate hyphae. Fungal culture of each of the above mentioned specimens revealed T. rubrum. Bacterial cultures were negative. A biopsy specimen of a nodule from the right forearm showed a dermal abscess with massive neutrophils in the center and macrophages in the border area (Figures 2A,B). The Periodic Acid Schiff (PAS) staining showed branched septate hyphae in the transition zone between granulomatous inflammation and abscess (Figure 2C). Fungal culture of the biopsy specimen also showed T. rubrum. Culture for non-tuberculous mycobacteria was negative. Furthermore, a biopsy specimen from the erythematous macula on the chest showed the histopathologic picture of tinea superficialis with branched septate hyphae in PAS staining. The patient was diagnosed as deeper dermatophytosis by T. rubrum presenting in form of multiple dermal abscesses. Treatment was started with oral itraconazole 200 mg per day and local application of ciclopirox twice a day. The patient did not show up for follow up and medication was only unsteadily taken. Four months later the patient presented again in our department with now multiple well-demarcated erythematous scaly plaques on the trunk and growing size of the abscesses on the right elbow. He had presented to an office-based doctor, where a drug eruption was assumed, why treatment with itraconazole was stopped. However clinical examination and biopsy specimen of the plaques revealed tinea superficialis. Nevertheless, a treatment change to griseofulvin 500 mg twice a day was conducted. Again, the patient took the medication only unsteadily which resulted in an improvement of the clinical outcome but no cure with nodules still present after 6 months.