Psoriasiform Contact Dermatitis Responding to High-Dose Folic Acid

Case Presentation

Austin J Dermatolog. 2014;1(2): 1010.

Psoriasiform Contact Dermatitis Responding to High-Dose Folic Acid

Peter J Aronson* and Jinmeng Zhang

Department of Dermatology, Wayne State University, USA

*Corresponding author: Peter J Aronson, Department of Dermatology, Wayne State University, Dingell Veterans Administration Medical Center, Dermatology 11-M DERM, 4646 John R, Detroit, MI 48201, USA

Received: April 27, 2014; Accepted: June 06, 2014; Published: June 10, 2014


We report a case of allergic contact dermatitis in a patch tested area with histopathologic examination showing psoriasiform dermatitis with that and another area with the same histopathology clearing using only daily oral doses of 6 mg folic acid, 100 mg vitamin B6 and 100 mcg vitamin B12. We found a negative correlation coefficient of -0.82 in aggregate for all psoriasiform dermatitis areas proven by biopsy. On the same patient other areas when biopsied showed lichen simplex chronicus. These areas in aggregate showed negative correlation of body surface area involved of only -0.52 despite treatment including not only the administration of these vitamins but also intralesional and topical corticosteroids and other topical immune modulators. High dose folic acid appears to be a potential therapy for patients with allergic contact dermatitis though this may only be appropriate in patients with high BMI and with comorbid signs of psoriasis.

Keywords: Contact dermatitis; Psoriasiform dermatitis; Folic acid; Leptin


BSA: Body Surface Area; eNOS: Endothelial Nitric Oxide Synthase; LSC: Lichen Simplex Chronicus; iNOS: Inducible Nitric Oxide Synthase


Folic acid is an important vitamin found in many food groups. In high doses it has been demonstrated to have an anti-inflammatory role in psoriasis. Here, we report the first case of psoriasiform contact dermatitis resistant to the standard treatment, yet responding to high-dose folic acid plus vitamins B6 and B12. We propose a possible mechanism based on literature support.

Case Presentation

A 78-year-old man (BMI=33.1) presented with an 8-year history of dyschromic plaques on feet, hands, thighs and hypomelanotic elbow plaques. Previous biopsies in 2005 showed sub acute dermatitis. He also noticed using naftifine gel caused him blisters.

Patch testing performed with the North American Standard 65-allergen series at 72 hours showed reactions to 8 allergens including propylene glycol and formaldehyde. Post testing he showed partial response to allergen avoidance, narrow band-UVB light and intralesional triamcinolone. Using topical clobetasol with propylene glycol and wearing formaldehyde-rich undergarments caused him flares. New scaly lichenified lesions and plaques developed on his legs, hips, buttocks, and at the patch testing site. Five months later, the lesions still remained. Biopsies of the right calf and the patch tested Area of the back demonstrated psoriasiform dermatitis (Figure 1). His vitamin B12 level was normal, and homocysteine level was 13.8umol/L (normal 5-15 μmol/L). He was prescribed daily folic acid 5 mg, vitamin B12 1 mg and B6 100 mg. However, initially the patient did not consistently ingest the full dose of folic acid due to pruritus caused by the vitamins. However after a 4 month-course, his homocysteine decreased to 10.2umol/L. He was also on 2 -10 day courses of prednisone 40 mg daily, which resulted in some plaque flattening. Topical clobetasol 0.05% spray (Galderma®) was prescribed, but after 2 months the rash still covered 2.4% of his Body Surface Area (BSA), with 1.7% on his back. Methotrexate was considered but interferon-γ release assay for tuberculosis (QuantiFERON®-TB Gold Test, Cellestis®) was positive.