Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Dermatitis Herpetiformis: Skin Manifestation of Celiac Disease (For Health Care Professionals) ?
    ### Response:
    A skin biopsy is the first step in diagnosing DH. Direct immunofluorescence of clinically normal skin adjacent to a lesion shows granular IgA deposits in the upper dermis. Histology of lesional skin may show microabscesses containing neutrophils and eosinophils.
    