Answer to last month's Clinical Quiz

Question:

A 78 years old lady has been suffering from multiple itchy and painful lesions of the trunk and limbs for two weeks. The oral and genital mucosae are not involved. The lesions are shown in the picture. Rubbing of the normal skin does not produce any lesions. There has been no preceding drug intake.

Answer:
A. Bullous pemphigoid

Bullous pemphigoid is an autoimmune disease commonly seen in middle-aged or elderly patients. It is characterised by tense blisters in limbs. Involvement of trunk may be seen when the disease is extensive. The blisters may arise on normal looking skin or erythematous skin. Mucosal involvement is uncommon. The skin is not mechanically fragile (i.e. Nikolsky sign is negative).

The diagnosis is confirmed by skin biopsy and detection of serum autoantibodies. Skin biopsy usually shows a subepidermal cleft with eosinophilic and neutrophilic infiltrate within the dermis and the blister cavity. Direct immuno-fluorescence study of the perilesional skin reveals immunoglobulins, commonly IgG and/or C3, along the dermoepidermal junction. In about 80% of patients, circulating autoantibodies can be found. The autoantibodies are of diagnostic value; the levels do not correlate with the disease activity so they are not useful for monitoring the disease.

Localised disease may respond to high-potency topical corticosteroids. Extensive disease usually requires oral corticosteroids, azathioprine or other immunosuppressive agents.