Interstitial Granulomatous Dermatitis with Arthritis (IGDA) is an uncommon dermatologic disorder.
Synonym: Ackerman's syndrome
Key features:
(1) figurate dermatitis with cutaneous cords (rope sign, may be absent)
(2) histiocytic infiltrate in the dermis
Clinical features:
(1) erythematous, annular, linear and arciform nodules and plaques
(2) the skin lesions are sharply demarcated, indurated and non-scaly
(3) arthritis in patients with a connective tissue disease
Histologic features:
(1) The inflammatory infiltrate shows a predominance of histiocytes but eosinophils, lymphocytes and neutrophils may be present. Occasional giant cells and small granulomas may be present.
(2) The infiltrate may be palisaded around degenerated collagen fibers.
