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.
Sanchez-Palacios
Carla
C
Department of Dermatology, Northwestern University Medical School, Chicago, IL 60612, USA.
Chan
Lawrence S
LS
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