Patient Case: Paraneoplastic Pemphigus (PNP)
A 62-year-old man presents to the dermatology clinic with a three-month history of painful oral ulcers and a worsening blistering rash on his trunk and extremities. He reports that the ulcers began as small, painful erosions in his mouth and later spread to his lips and throat, making it difficult to eat. Over the past month, he has developed flaccid blisters and erosions, which have progressively worsened despite treatment with topical steroids.
His past medical history is significant for weight loss, fatigue, and night sweats over the last six months. He was recently diagnosed with a mediastinal mass, which is undergoing further evaluation.
On examination, he has widespread erosions and flaccid blisters on the trunk, face, and extremities, along with severe mucosal involvement, including painful ulcerations in the oral cavity, lips, and conjunctiva. A Nikolsky sign is positive (skin shears off with slight pressure).
A skin biopsy with direct immunofluorescence shows intercellular and basement membrane IgG deposits, consistent with paraneoplastic pemphigus (PNP). Further testing reveals that the mediastinal mass is a B-cell lymphoma. The patient is started on immunosuppressive therapy and chemotherapy to treat the underlying malignancy.
- What is the most likely diagnosis in this patient?
a) Pemphigus vulgaris
b) Bullous pemphigoid
c) Paraneoplastic pemphigus (PNP)
d) Stevens-Johnson syndrome - Which clinical feature most strongly suggests paraneoplastic pemphigus (PNP) rather than other blistering disorders?
a) Tense blisters on trauma-prone areas
b) Severe mucosal involvement with painful oral ulcers and conjunctival erosions
c) Itchy, grouped vesicles on extensor surfaces
d) Blistering rash without systemic symptoms - What is the most important next step in managing a patient with suspected paraneoplastic pemphigus?
a) Prescribe high-dose systemic corticosteroids
b) Perform a skin biopsy and search for an underlying malignancy
c) Treat with topical corticosteroids and antihistamines
d) Order a bacterial culture of blister fluid - Which underlying malignancy is most commonly associated with paraneoplastic pemphigus?
a) Squamous cell carcinoma
b) Chronic lymphocytic leukemia and non-Hodgkin lymphoma
c) Basal cell carcinoma
d) Malignant melanoma
