Board review: immunobullous patterns
Blister level, immunofluorescence pattern and clinical associations in the major autoimmune blistering diseases.
Updated: 2026-09-13
Written for clinicians and medical students
This section is a teaching reference for doctors, residents and medical students. It is not patient guidance and not a substitute for clinical examination, and it must not be used for self treatment.
Pattern table
| Disease | Level and DIF | Classic clue |
|---|---|---|
| Pemphigus vulgaris | Suprabasal; intercellular IgG/C3 | Flaccid blisters, painful oral erosions |
| Pemphigus foliaceus | Subcorneal; intercellular IgG/C3 | Superficial crusting, no mucosal disease |
| Bullous pemphigoid | Subepidermal; linear IgG/C3 at basement membrane | Older adult, tense itchy bullae |
| Dermatitis herpetiformis | Subepidermal; granular IgA in dermal papillae | Grouped extensor vesicles, coeliac association |
| Linear IgA disease | Subepidermal; linear IgA at basement membrane | Annular string-of-pearls pattern, especially in children |
Specimen strategy
- Take a fresh intact blister edge for routine histology and separate perilesional, normal-appearing skin for direct immunofluorescence [1].
- Do not place the immunofluorescence specimen in formalin; use the laboratory-specified transport medium.
- Consider salt-split skin and antigen-specific serology when the linear basement-membrane pattern requires further classification [2].