Review Question - QID 106259

Based on clinical exam findings and direct immunofluorescence (IF), this patient is suffering from pemphigus vulgaris, which is a disease that results from autoimmune antibodies against desmoglein 3, a component of desmosomes.

Pemphigus vulgaris is an autoimmune blistering disorder that typically presents in middle-aged adults. Its characteristic fragile blistering can occur from the face to the trunk and does not spare the mucosa. It results from an autoimmune reaction against desmoglein 3 in the macula adherens, or desmosome, which is responsible for attaching adjacent epithelial cells to one another. IF, as shown, is sometimes described as a net-like distribution of keratinocytes.

Bickle et al. describe autoimmune bullous dermatoses, of which pemphigus vulgaris is noted to usually start in the oral mucosa followed by blistering of the skin. This skin blistering is often painful, consistent with the patient in this vignette's presentation.

Yeh et al. discuss treatment options for pemphigus vulgaris. Oral dapsone is considered a first-line agent primarily because the risk of fatal side effects is lower than that of other available agents. They describe alternative treatments, such as IVIg therapy which has been reported to be beneficial in some patients. The adverse effects from IVIg therapy are minimal and this treatment modality may allow the discontinuation of more dangerous oral agents.

Figure A demonstrates characteristic fragile blistering and underlying ulceration of pemphigus vulgaris. Figure B shows a biopsy specimen under IF as described above. Note "fish-net" appearance of fluorescence, as opposed to only at the basement membrane which would be expected in bullous pemphigoid.

Incorrect Answers:
Answer 2: Desmopenetrin is a protein component of hemidesmosomes. Bullous pemphigoid, a similar, milder skin disease, affects hemidesmosomes.
Answer 3-5: The gap junctions, intermediate junctions, and tight junctions are not involved in pemphigus vulgaris.