Onset of psoriatic arthritis is commonly insidious, with symptoms often observed first in the distal interphalangeal joints. Presence of psoriatic skin or nail disease, or both, is mandatory for unequivocal diagnosis. Reiter's syndrome has many features in common with psoriatic arthritis. However, urethritis is usually the first symptom, followed by conjunctivitis and then arthritis. Principles of management of both conditions are similar to those of rheumatoid arthritis.