Interactive Case Study - May 2020

A 59-year-old man presented with a history of a rash on his torso and upper extremities

Rachel Sennett, MD, PhD; Maya Farah, MD; Lynne J. Goldberg, MD

A 59-year-old man presented with a six-month history of a rash on his torso and upper extremities with mild associated itching. Physical exam revealed multiple non-scaly, partially blanchable, reddish-brown patches, approaching near confluence on the chest, back, and proximal extremities. Review of systems was notable for occasional knee pain and fatigue. Lab work revealed a positive ANA (1:80), elevated ESR (25 mm/hr), negative RPR, and was otherwise unremarkable. Biopsy of one of the lesions on the forearm revealed the following histopathologic findings (Figures 1-5).

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

What is the best diagnosis?

A.	Actinic granuloma

B.	Granuloma annulare

C.	Granulomatous drug reaction

D.	Lyme disease

E.	Palisaded and neutrophilic granulomatous dermatitis