(BMJ) - An 18-day-old baby with normal birth hx presented with a new rash of sharply demarcated, red, irregularly-shaped papules and plaques. The baby appeared well w/o lymphadenopathy or organomegaly. Blood work confirmed the diagnosis. What is it?
Tinea corporis
Neonatal psoriasis
Staphylococcal scalded skin syndrome
Herpesvirus 6-associated urticaria multiforme
Allergic reaction to diaper cream
You are correct. Real-time PCR for viral DNA revealed human herpesvirus 6 (HHV-6) infection; other serological tests and cultures were negative. Three days after admission, the skin lesions completely resolved. Antibiotic therapy was stopped and patient was discharged. At 1-mo follow-up, HHV-6 DNA had decreased and the infant remained well without recurrence of rash.
(BMJ) - A 21-yo man on azathioprine for Crohn dz presents w/ fever + pancytopenia. No response to abx, GCSF, or AZA withdrawal. Labs: high TGs, ferritin; low fibrinogen. Bone marrow: unusual macrophage. Ileum histology: CMV infection. What is the diagnosis?
Multiple myeloma
Arsenic poisoning
Hemophagocytic lymphohistiocytosis
Azathioprine toxicity
Hepatitis C
You are correct. Hemophagocytic lymphohistiocytosis (HLH) is also known as macrophage activation syndrome, or reactive hemophagocytic syndrome. HLH is a syndrome of excessive macrophage activation often triggered by a viral infection in immunosuppressed pts. Activated macrophages phagocytose blood cell precursors, causing pancytopenia. HLH is treated with prompt immunosuppression, supportive care, and tx of the underlying infection. This patient made a full recovery after immunosuppressive and antiviral tx.
(BMJ) - A 64-yo woman presented w/ weakness, UTI, and vesicular eruption on left lower back and right thigh. PMHx: type 2 DM, prior stroke, and polymyositis. Medication: prednisone 20 mg daily. Labs: CRP was 3.7, others were WNL. What is the rash?
Behçet disease
Herpes zoster duplex bilateralis
Drug reaction
Contact dermatitis
Herpes simplex
You are correct. Herpes zoster is usually confined to a single, unilateral dermatome. This patient had typical vesicular zoster eruption simultaneously in dermatomes D8 and L4, perhaps due to her immunosuppression. She was treated with IV acyclovir 10 mg/kg TID with gradual improvement and crusting of lesions. She was free of recurrence at 2 mo follow-up.
(BMJ) - A 30-yo cyclist skidded on a wet road and struck his head on a curb. He was alert and oriented with normal vital signs. Blood was noted originating from the left external auditory meatus, leaving a halo on the sheet. What is the diagnosis?
Basilar skull fracture
Maxillary sinus fluid leak
Hemorrhagic mastoiditis
Ear foreign body
Ruptured tympanic membrane
You are correct. The halo, or double-ring, sign occurs when CSF is mixed with blood in proportions of 30% to 90%. This sign, along with the blood and CSF separated into 2 layers in the cavum conchae, are classic findings of basilar skull fracture. CT confirmed the diagnosis. The patient was managed conservatively and discharged 3 days later when the CSF leak had stopped.
(BMJ) - A 2.7-kg boy was delivered as breech vaginal birth after uncomplicated pregnancy. The infant was well w/ normal exam except for multiple white nodules along alveolar ridge of maxilla that did not interfere with nursing. What are they?
Primordial cysts
Mucoceles
Bohn nodules
Natal teeth
Epstein pearls
You are correct. Bohn nodules are benign, self-limiting, smooth, white, keratin-filled cysts found most frequently on the maxillary arch. They are more common in term vs preterm infants. In contrast, Epstein pearls would be found on the palate; natal teeth on the mandibular ridge; and mucoceles on the labial mucosa. Primordial cysts would be seen in place of a tooth that is missing.
A 79-yo woman with PMHx of Wegener’s granulomatosis presented with hyperpigmentation of arms, face, and legs. Medication: methotrexate. Adrenal function and ACTH level normal. What is the diagnosis?
Methotrexate-associated hyperpigmentation
Cushing disease
Addison disease
Acanthosis nigricans
Solar lentigo
You are correct. Hyperpigmentation is a rare but reversible side effect of methotrexate. The patient’s methotrexate was stopped, and the hyperpigmented areas of skin began to return to normal.