Clinical Pathologic Mismatch in a TNF-α Inhibitor-Associated Drug Reaction

A 56-year-old Caucasian male with a history of chronic plaque psoriasis, primary sclerosing cholangitis status-post liver transplant on tacrolimus, and ulcerative colitis on infliximab developed a progressive erythematous eruption with associated fatigue, anorexia, myalgias, and arthralgias. On two separate occasions, his skin biopsy demonstrated a lichenoid interface dermatitis (LID). Despite multiple courses of oral prednisone, topical steroids, and a short course of hydroxychloroquine, his symptoms continued to relapse and remit. When a temporal association between increasing his infliximab dose and the global progression of his disease was identified, he was ultimately diagnosed with a TNF-α inhibitor-induced psoriasis flare. Despite the patient's long-standing history of psoriasis, a plausible psoriasis rebound reaction after systemic steroids was not strongly considered in light of his histopathology. Though lichenoid interface dermatitis is a commonly reported histologic finding in patients on TNF-α inhibitors, it has scarcely been reported in patients with psoriasiform eruptions clinically.

Idiopathic toxic epidermal necrolysis in an adolescent.

A 10-year-old girl, suspected 2 days prior to have streptococcal pharyngitis, presented with diffuse erythema, tense bullae, Nikolsky-positive desquamation, as well as ulcerations of her oral and genital mucosa. She denied recent travel, sick contacts, or preceding and concurrent use of medications, including over-the-counter and herbal supplements. A comprehensive viral polymerase chain reaction (PCR) panel, Mycoplasma pneumoniae PCR and IgM, streptococcal molecular antigen test, urine culture, blood culture, and rheumatologic serologies were negative. Based on the patient's clinical presentation and biopsy results, she was diagnosed with idiopathic toxic epidermal necrolysis.