Diagnosis is sometimes difficult because the early phases of the disease often resemble eczema or even psoriasis. As with any serious disease, it is advisable to pursue the opinion of a medical professional if a case is suspected. Diagnosis is generally accomplished through a skin biopsy. Several biopsies are recommended, to be more certain of the diagnosis. The diagnosis is made through a combination of the clinical picture and examination, and is confirmed by biopsy.
To stage the disease, various tests may be ordered, to assess nodes, blood and internal organs, but most patients present with disease apparently confined to the skin, as patches (flat spots) and plaques (slightly raised or 'wrinkled' spots).
Peripheral smear will often show buttock cells.[4]