Step 1: View clinicals

A 54-year-old woman presents with a 2-month-history of multiple erythematous lesions over both lower extremities. They first appeared over the lower leg, with slow upward extension up to the knees. The lesions are palpable, but not pruritic, painful, or tender. She also experienced on and off generalized arthralgia and myalgia for the same time period. There was no history of swollen joints. Neither were there constitutional symptoms nor significant weight loss. Her medical history is unremarkable except for mild depression for one year, after losing her job as an administrative assistant. This was treated as an outpatient, in the psychiatry clinic. Currently, she is not taking any medications and is not known to have any allergies. She does not smoke and only drinks socially. She used IV heroin and cocaine for almost half-a-decade, in her 20s, but managed to stop after a program of rehabilitation, along with strong family support. She has remained drug-free since then.

Step 2: Order all relevant investigations

Complete Blood Count + Liver Profile + Renal Profile

Complete blood count ------------------------ WBC: 8,500/mm3 (4,600-11,000) Hb: 14.2 g/dL (11-18) Plt: 312,000/mm3 (150,000-400,000) Liver profile ------------- ALT: 34 U/L (9–51) AST: 21 U/L (13–40) ALP: 80 U/L (34–122) GGT: 40 U/L (13–58) Tot. bilirubin: 0.4 mg/dL (0.1–1.1) Conj. bilirubin: 0.1 mg/dL (0–0.3) Albumin: 4.5 mg/dL (3.5-5.5) INR: 1.0 (0.9-1.1) Renal profile -------------- Blood urea nitrogen: 12 mg/dL (7–23) Serum creatinine: 0.6 mg/dL (0.5–1.5) Sodium: 140 mEq/L (135-145) Potassium: 4.0 mEq/L (3.5-5.5)

Autoimmune Screen

ANA: negative dsDNA: negative c-ANCA: negative p-ANCA: negative Rheumatoid Factor: positive C3 levels: within the normal range C4 levels: low

HIV + Hepatitis Panel

HIV antigen: negative HIV antibodies: negative Hepatitis B core antibody (HBcAb): negative Hepatitis B surface antigen (HBsAg): negative Hepatitis C antibody: positive

Cryoglobulin Screen

A cryocrit of 5% is observed. Electrophoresis and immunofixation reveal monoclonal IgM and mixed polyclonal IgG.

Step 3: Select appropriate management

Hepatitis C Antiviral Therapy

Score: ★★☆