Arthritis (DIP), nail changes, myopathy, eteropathy, AIDS, assoc.
AI and environmental factors like stress, smoking, ETOH, etc
Pink/salmon plaque w/ silver white scales, extensor surface
Auspitz sign (point bleeding) and Koebner phenomenom (new lesions at site of trauma)
Acanthosis with thinning of stratum granulosum over dermal papillae