Skin nontumor
Vesiculobullous and acantholytic reaction patterns
Dermatitis herpetiformis
Topic Completed: 1 July 2011
Minor changes: 23 July 2020
Copyright: 2002-2020, PathologyOutlines.com, Inc.
PubMed Search: Dermatitis herpetiformis [title]
Table of Contents
Definition / general | Terminology | Epidemiology | Clinical features | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Immunofluorescence images | Positive stains | Differential diagnosisCite this page: Hamodat M. Dermatitis herpetiformis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumordermatitisherpetiformis.html. Accessed October 28th, 2020.
Definition / general
- Uncommon autoimmune blistering disorder associated with gluten-sensitive enteropathy; very pruritic (eMedicine, J Am Acad Dermatol 2011;64:1017)
- Involves extensor surfaces of elbows, knees, buttocks and back; also chest, axillae, neck, posterior shoulder and extensor aspects of the limbs; may involve hairless skin and oral mucosa
Terminology
- Also called keratosis follicularis
Epidemiology
- Ages 20 - 39 years; more common in males
Clinical features
- Herpetiform because vesicles are small (pinhead sized) and grouped symmetrically, as with herpes
- May appear as erosions due to intense scratching
Treatment
- Dapsone, 50 - 200 mg/day; causes dramatic response, so the drug is administered for diagnostic and therapeutic purposes
- Rash returns 2 - 3 days after Dapsone is discontinued
- Gluten free diet may cause prolonged remission in some patients or lower daily Dapsone requirement in others
Clinical images
Images hosted on other servers:
Various images
Microscopic (histologic) description
- Subepidermal multilocular blister with papillary neutrophilic microabscesses that may contain eosinophils, basal cell vacuolization
- Dermal infiltrate is mixed, with lymphocytes, histiocytes and abundant neutrophils
- Karyorrhexis (nuclear dust within dermis) is characteristic
- No vasculitis
Microscopic (histologic) images
Images hosted on other servers:
Subepidermal blister with microabscess
Immunofluorescence images
Images hosted on other servers:
Granular IgA deposits in the dermal papillae
Positive stains
- Granular IgA pattern in dermal papillae by direct immunofluorescence
- No circulating antibodies
Differential diagnosis
- Bullous pemphigoid: large tense blisters on flexor surfaces, trunk, intertriginous regions and mucosa; no microabscesses
- Linear IgA dermatosis: homogenous band of IgA at the dermal-epidermal junction; no anti-endomysial or anti-tissue transglutaminase IgA antibodies; not gluten sensitive
