Idiopathic itch, rash, and urticaria/angioedema merit serum vitamin D evaluation: a descriptive case series.

Background: Vitamin D insufficiency is epidemic. Rarely are cutaneous consequences attributed to low vitamin D.

Methods: A retrospective case series of 63 patients describes an association of pruritus, rash, and urticaria/angioedema with low 25-hydroxyvitamin D (25[OH]D <32 ng/mL). The 90% (57/63) of patients with low vitamin D were treated with 8 to 12 weeks of vitamin D 50,000 IU weekly followed by daily supplementation. Concurrent diagnoses were treated routinely. Complete resolution of cutaneous symptoms defined response.

Results: Patients were 3 to 80 years of age. The 90% (57/63) with low vitamin D (25[OH]D < 32 ng/mL) had a mean age of 47 (11 to 80) years old, 70% were atopic, and 77% were female. Median duration of idiopathic cutaneous symptoms was 18 months. Mean 25[OH]D was 18.0 ng/mL. With vitamin D treatment 70% (40/57) had complete resolution of symptoms. Mean 25[OH]D for vitamin D responsive patients (16.8 ng/mL) was significantly lower than for vitamin D non-responsive treated patients (20.9 ng/mL, P = 0.02 by unpaired t-Test). Resolution of cutaneous symptoms with vitamin D supplementation occurred in a mean of 4.2 weeks. Symptom recurrence was seen in subsequent months only if vitamin D insufficiency recurred.

Conclusion: This retrospective case-series, with a 70% (40/57) vitamin D treatment success, suggests that vitamin D status should be assessed in patients with idiopathic cutaneous symptoms. If vitamin D is low, symptom resolution is often possible with oral supplementation of vitamin D. Controlled clinical studies are required to confirm these associations.