Information ⬇
Editors
Chronic Bullous Diseases (Dermatitis Herpetiformis, Pemphigoid)
Essentials
- Dermatitis herpetiformis (DH) and pemphigoid should be recognized as causes of chronic bullous dermatitis.
- Patients should be referred to a dermatologist for diagnosis and planning of treatment.
- DH-patients must always be referred to investigations to establish possible coeliac disease.
Dermatitis herpetiformis (skin coeliac disease)
Diagnosis
- Typical vesicles (pictures 1 2) on erythematous skin, and scratches on the elbows and knees (pictures 1 2), sacrum, buttocks (picture 3) and scalp.
- Ordinary histopathology is usually non-specific, but immunohistopathology is useful.
- Coeliac disease should be excluded primarily by measuring transglutaminase antibodies. See Coeliac Disease for details.
- Gastroscopy and small bowel biopsy are indicated before starting diet therapy.
- Remember to ask about other cases in the family.
Treatment
- A gluten-free diet has a favourable effect on the skin symptoms in cases of dermatitis herpetiformis even if the patient does not have coeliac disease. Adequate diet councelling is essential.
- Dapsone quickly relieves the skin symptoms but its use bears a risk of haemolysis. Repeated laboratory examinations (monitoring of blood picture as well as liver and kidney function) and clinical follow-up are absolutely necessary.
- Local glucocorticoids may alleviate the skin symptoms.
Indications for specialist consultation
- A specialist should always be consulted on the diagnosis and treatment of dermatitis herpetiformis. In stabile phase, follow up may be done by a general practitioner.
Pemphigoid
Definition
- An autoimmune disease of the elderly presenting with vesicles or large bullae. Skin basal membrane antibodies are present.
Symptoms
- Pemphigoid affects mainly elderly people (> 60 years of age)
- Sometimes starts with a generalized itch.
- Large thick-walled, translucent, and itching vesicles or bullae develop on erythematous skin of the trunk and proximal parts of the extremities (pictures 4 5).
- Mucosal surfaces are usually unaffected, but a form restricting solely to the mucosal surfaces is also encountered (picture 6).
- The general condition of the patient is unaffected.
Diagnosis
- In pemphigoid, over 90% of the patients have anti-basement membrane antibodies that react with the epidermal basement membrane zone (hemidesmosomes). Anti-basement membrane antibodies may already be positive at the itching phase even if actual bullae are not yet seen. The anti-basement membrane antibody test is unspecific and therefore it is recommended to carry out serum anti-BP180 antibody test.
- A biopsy should be taken from the side of a fresh (small) vesicle or from an erythematous skin lesion. If a vesicle is biopsied the complete base of the vesicle should be included in the specimen.
- The epithelium under an older vesicle has often already regenerated, and interpretation of the histology is difficult. Immunohistology is diagnostic.
- A fresh biopsy specimen is required for immunofluorescence (IF) studies. The specimen is put directly into dry ice or liquid nitrogen, or a special container with so-called Michelin transport medium can be used.
Differential diagnosis
- Pemphigus (vulgaris, foliaceus, erythematosus, vegetans)
- The age distribution is wider.
- Very rare in comparison with pemphigoid.
- Immunohistology is diagnostic.
- More difficult to treat than pemphigoid. Pemphigus vulgaris may be life threatening.
- Epidermolysis bullosa
- Porphyrias Porphyrias
- P. cutanea tarda presents with vesicles on the dorsa of the hands
- Rare
- Dermatitis herpetiformis
- Sometimes presents as a widespread disease that is difficult to identify.
- Systemic glucocorticoids are the first-line treatment. The dose is individual. The initial dose is prednisolone 0.5 mg/kg/day. Continuous medication is seldom needed.
- Tetracycline may also be effective.
- Treatment with dapsone, as well as adjuvant therapies with glucocorticoids combined with other immunosuppressive drugs or methotrexate is carried out under the responsibility of a dermatologist.
- Local treatment with very potent glucocorticoids may suffice in limited disease.
Indications for specialist consultation
- Confirmation of the diagnosis and differential diagnosis (immunohistology) are tasks of a specialist. The patient should be referred without delay.
- The treatment is best started by a specialist. Often the disease continuously behaves in the same manner in the same patient. After a treatment regime has been found that is the least demanding for the patient it can be repeated under the management of a general practitioner as the disease recurs.
Evidence Summaries ⬆