Sandwich sign

Sandwich sign

This refers to a layered stratum corneum where there are two patterns of stratum corneum overlying each other. It is a clue to a dermatophyte infection. There may be two different types of orthokeratosis e.g. basketweave and layered or parakeratosis under orthokeratosis.

This sign can also be seen in the acute phase of a proliferative disorder e.g. pityriasis lichenoides  PLEVA variant where parakeratosis underlies the usual orthokeratosis. The same thing may occur with psoriasis and some acute erythema multiformes.

View the Sandwich Sign