The patient had been diagnosed with pemphigus vulgaris (PV) 1 year prior to presentation with erosions on the axilla. Biopsy at that time revealed intraepithelial acantholytic blistering with areas of suprabasilar and subcorneal clefting. Direct immunofluorescence was positive for linear/granular IgG deposition throughout the epithelial cell surfaces, as well as linear/granular C3 deposits of the lower two thirds of the epithelial strata, consistent for pemphigus vulgaris.
There is likely a genetic predisposition. Medications that may induce pemphigus include penicillamine, nifedipine, or captopril.
Clinically, PV presents with flaccid blistering lesions that may be cutaneous and/or mucosal. Bullae can progress to erosions and crusting, which then heal with pigment alteration but not scarring. The most commonly affected sites are the mouth, intertriginous areas, face, and neck. Mucosal lesions can involve the lips, esophagus, conjunctiva, and genitals.
Biopsy for histology and direct immunofluorescence is important in distinguishing between PV and other blistering disorders. Up to 75% of patients with active disease also have a positive indirect immunofluorescence with circulating IgG.
There are numerous reports in the literature of PV occurring in previous surgical scars, and areas of friction or trauma. This so-called Koebner’s phenomenon is seen more commonly in several dermatologic conditions, such as psoriasis, lichen planus, verruca vulgaris, and vitiligo.
Dr. Donna Bilu Martin
Treatment for PV is generally immunosuppressive. Systemic therapy usually begins with prednisone and then is transitioned to a steroid sparing agent such as mycophenolate mofetil. Other steroid sparing agents include azathioprine, methotrexate, cyclophosphamide, and intravenous immunoglobulin. Secondary infections are possible and should be treated. Topical therapies aimed at reducing pain, especially in mucosal lesions, can be beneficial.
Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Florida. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to dermnews@mdedge.com.
References
Cerottini JP et al. Eur J Dermatol. 2000 Oct-Nov;10(7):546-7.
Reichert-Penetrat S et al. Eur J Dermatol. 1998 Jan-Feb;8(1):60-2.
Saini P et al. Skinmed. 2020 Aug 1;18(4):252-253.