A 72-year-old woman presents with pruritus for the past 6 weeks. She is careful to moisturize her skin after her daily shower and uses soap sparingly. The itching is diffuse and keeps her awake at night. Over this time she has lost 15 lb of weight and has noticed diminished appetite. She has previously been healthy and takes no medications. Physical examination shows no evidence of rash; a few excoriations are present. She appears fatigued with mild temporal muscle wasting. The general examination is otherwise unremarkable.
What is the best next step in her management?
A. Topical corticosteroidsIn 20% of cases, diffuse itching is a manifestation of systemic illness. Renal insufficiency, obstructive liver disease (especially primary biliary cirrhosis), hematological conditions such as polycythemia vera or lymphoma, and thyroid disorders can all present in this fashion. Although most patients with pruritus will have dry skin (xerosis) or dermatitis (usually the primary dermatitis is apparent from the examination), this patient’s weight loss and anorexia should prompt a search for an underlying disorder. Topical agents, oral antihistamines, or doxepin (a tricyclic antidepressant with potent H 1 and H2 blocking effects) can be used for symptomatic purposes but should not replace a search for an underlying cause in this elderly patient with new onset of symptoms. Depression can cause weight loss,but severe pruritus would be an unlikely presenting symptom. Excoriations are nonspecific manifestations of scratching; unless a specific primary lesion (eg, papule, vesicle) is found, skin biopsy will rarely be helpful in the evaluation of pruritus.