The diagnosis of Gianotti–Crosti syndrome is clinical. A validated diagnostic criterion is as follows: A patient is diagnosed as having Gianotti–Crosti syndrome if: • On at least one occasion or clinical encounter, he/she exhibits all the
positive clinical features, • On all occasions or clinical encounters related to the rash, he/she does not exhibit any of the
negative clinical features, • None of the
differential diagnoses is considered to be more likely than Gianotti–Crosti syndrome on clinical judgment, and • If lesional biopsy is performed, the histopathological findings are consistent with Gianotti–Crosti syndrome. The
positive clinical features are: • Monomorphous, flat-topped, pink-brown papules or papulovesicles 1-10mm in diameter. • At least three of the following four sites involved – (1) cheeks, (2) buttocks, (3) extensor surfaces of forearms, and (4) extensor surfaces of legs. • Being symmetrical, and • Lasting for at least ten days. The
negative clinical features are: • Extensive truncal lesions, and • Scaly lesions.
Differential diagnosis The
differential diagnoses are:
acrodermatitis enteropathica,
erythema infectiosum,
erythema multiforme,
hand-foot-and-mouth disease,
Henoch–Schönlein purpura,
Kawasaki disease,
lichen planus,
papular urticaria, papular purpuric gloves and socks syndrome, and
scabies. ==Treatment==