Along with typical clinical forms of skin sarcoidosis, there are numerous atypical forms, which are usually observed in patients with visceral sarcoidosis. Wide variety of atypical forms of dermatological manifestations of the disease complicate clinical diagnosis of sarcoidosis, which can be identified based on biopsy studies. The article describes in detail the morphological criteria for the histological diagnosis of granulomatous process in patients with sarcoidosis, which are the same in both typical and atypical of dermatological lesions and in the case of sarcoidosis of other organs. The results of two our own observations are provided to illustrate the difficulties of the diagnosis of generalized sarcoidosis with atypical skin manifestations. We describe the clinical case of sarcoidosis with skin rash similar to Biett erythema or Devergie disease, and also a disease, where exanthemas were similar to pink acne on the face and to prurigo or vasculitis on the lower extremities. It was shown that diagnostic challenges could be successfully solved by biopsy studies of the lesion foci.