Posted by a Family Medicine Physician:

An older patient presented with a worsening skin rash that was initially diagnosed as eczema, but did not respond to steroids, antibiotics, or topical lotions. The patient had a history of allergies and was suspected of being bitten by a spider, but tests were inconclusive. A dermatologist on Figure 1 suggested that the rash was caused by psoriasis and that a high potency topical steroid and calcipotriene, a topical form of vitamin D, should be used. The treating physician later confirmed the diagnosis made by the community.