(BMJ)—A 59-yo hairdresser presented w/ painless lumps on his R index finger. He reported a 20-yr hx of recurrent infxn in the area, treated w/ multiple courses of abx. Exam: lobulated mass on ulnar border of R index finger, w/ sinus exiting proximally. What is the dx?
Tuberculosis verrucosa cutis
Onychomycosis
Basal cell carcinoma
Periungual pilonidal sinus
Ganglion cyst
You are correct. Periungual pilonidal sinus was confirmed when excision under local anesthesia revealed foreign hair strands of multiple colors. This condition is a recurrent occupational hazard for hairdressers, animal groomers, and shearers, where freshly cut hairs penetrate the eponychium and trap subcutaneously. Interdigital pilonidal sinus (barber’s dz) is the more common presentation.

BMJ 2017;359:j5520

(BMJ)—An 82-year-old woman on MTX x5mo for rheumatoid arthritis and valacyclovir x5 days for presumed herpes labialis presented with worsening of lip crusting and bleeding. Exam: bloody crusts and epithelial detachment of lips; skin and mucus membranes otherwise clear. Labs: macrocytic anemia. What’s the dx?
Squamous cell carcinoma
Actinic cheilitis
Scurvy
Behcet syndrome
Methotrexate reaction
You are correct. Severe labial erosions are rare with MTX, though mild mucositis and oral ulceration are common. Adverse reactions to MTX are more common in patients with advanced age, renal failure, drug interactions, or folate-dependent enzyme polymorphisms. The MTX was discontinued, and IV calcium folinate was given at 36 mg/day. The labial erosions epithelialized in 10 days, and the anemia improved in 3wk. Sulfasalazine and prednisolone were started in place of MTX.

BMJ 2017;359:j5063