Psoriasis - Learn about the causes, symptoms, diagnosis & treatment from the Merck Manuals - Medical Consumer Version. Pictures of Soriatane (Acitretin), drug imprint information, side effects for the patient. Pustular [PUHS-choo-lar] psoriasis is characterized by white pustules (blisters of noninfectious pus) surrounded by red skin. The pus consists of white blood cells. It is not an infection, nor is it contagious. Pustular psoriasis is primarily seen in adults. It may be limited to certain areas of the Psoriasis is not contagious and can’t be spread through contact or exchange of bodily fluids. hi, i have psoriasis and psoriatic arthritis, Is it ok to donate blood? I've always wanted to, but because i'm always feeling sick i didnt know if it is the right thing to do. Diagnosis. Your doctor makes a diagnosis of lichen planus based on your symptoms, your medical history, a physical examination and, if necessary, the results of lab tests. Treatment with systemics. Generally, women and men should avoid the use of systemic medications for psoriasis when trying to conceive. Systemic medications for psoriasis should also be avoided when nursing as the drugs can be secreted in breast milk. Read about the side effects associated with various types of psoriasis medications, including prescription oral and topical drugs. Diagnosis. In most cases, diagnosis of psoriasis is fairly straightforward. Physical exam and medical history. Your doctor usually can diagnose psoriasis by taking your medical history and examining your skin, scalp and nails. Acitretin is a retinoid, which is a form of vitamin A. Acitretin is used to treat severe psoriasis in adults. Acitretin is not a cure for psoriasis, and you may relapse after you stop taking this medication.