Development of pemphigus herpetiformis in a patient with psoriasis receiving UV-light treatment.
BACKGROUND
Pemphigus is an autoimmune blistering disease of the skin and mucous membranes. Pemphigus herpetiformis, a rare variant of pemphigus, is characterized by erythematous, vesicular, bullous, or papular lesions in a herpetiform pattern, often associated with pruritus. Clinical cases documenting the development of pemphigus in patients with a history of psoriasis have been reported in the literature.


METHODS
We used immunological methods to study a case in which pemphigus herpetiformis occurred in a woman with a history of psoriasis, shortly after a course of ultraviolet B (UVB) therapy.


RESULTS
Histopathology revealed a subcorneal blister with prominent neutrophilic infiltration. Immunopathology detected in situ bound and circulating immunoglobulin G (IgG) autoantibodies to epithelial cell surfaces and circulating IgG autoantibodies against desmoglein 1. The patient was also found to have Hashimoto's thyroiditis.


CONCLUSIONS
This case illuminates a possible role of UV therapy in the induction of pemphigus herpetiformis through an epitope-spreading mechanism. The patient's autoimmune thyroiditis may also contribute to the predisposition for pemphigus development. The histopathological findings in pemphigus patients with a history of psoriasis may resemble Munro's microabscesses of psoriasis and should therefore alert pathologists and clinicians in considering additional diagnostic methods such as direct and indirect immunofluorescence.
Department of Dermatology, Northwestern University Medical School, Chicago, IL 60612, USA.
Carla
C
Sanchez-Palacios
Lawrence S
LS
Chan
D000328:Adult; D005260:Female; D006801:Humans; D010392:Pemphigus / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D011241:Prednisone / Q000627:therapeutic use; D011565:Psoriasis / Q000150:complications / Q000473:pathology* / Q000532:radiotherapy*; D012867:Skin / Q000473:pathology* / Q000528:radiation effects; D016896:Treatment Outcome; D014467:Ultraviolet Therapy / Q000009:adverse effects*
D011241:Prednisone