Clinical assessment in the workplace: dermatitis

The clinical assessment of dermatitis in the workplace is put forward as a series of four decisions: (1) Is it dermatitis and not psoriasis, tinea, scabies, etc? (2) Is it contact dermatitis and not atopic, seborrhoeic, discoid, stasis or unclassified eczema? (3) Is it irritant contact dermatitis or allergic contact dermatitis? (4) What is/are the probable cause(s)