Contact urticaria from panthenol in hair conditioner.

Panthenol is the alcohol corresponding to pantothenic acid, with the formula HOCH 2 C(CH 3) 2 CHOHCONH(CH 2) 2 CH 2 OH. It is a member of the vitamin B complex (B 5) and a component of coenzyme A. Panthenol is produced synthetically from 2,4-dihydroxy-3,3-dimethylbutyric acid and b-alanine. Common sources are food products such as liver, kidney, yeast, crude molasses, whole grain cereals, milk and rice (1). Panthenol is also a common additive to hair-care products as a conditioning agent (2). Case Report A 53-year-old woman, with a previous history of allergic contact dermatitis from balsam of Peru (Myroxylon Per-eirae), nickel and benzoyl peroxide, presented with an account of facial edema, erythema and pruritus within a minute after application of a new hair conditioner, DHS Conditioner with Panthenol. She had no shortness of breath but did have diffuse pruritus on her trunk. There was gradual improvement of her symptoms over an hour, after washing off the conditioner. She had previously used panthenol-containing hair coloring products at her hairdresser, with pruritus occurring at the hairline. The patient was open tested on the volar forearm for 30 min with panthenol 30% pet. and to suds from a 1:5 mixture of her conditioner and water. The tests were negative. The patient was then prick tested through the panthenol and conditioner suds, as well as to histamine hydro-chloride (10 mg/ml) and saline solution (0.9%) as positive and negative controls, respectively. Pruritus and erythema began 2 min after pricking and wheals formed within 5 min. After 20 min, the wheals were read as: panthenol, 3π, DHS Conditioner suds, 1π, according to the rating system described by Kanerva et al. (3). The histamine reaction was equal to the panthenol reaction and the saline was completely negative at 30 min after pricking. The patient discontinued usage of panthenol-containing conditioner after the 1st episode described above. We spoke with the patient 1 month after prick testing. She reported pruritus and swelling at the hairline after her hairdresser again used panthenol-containing hair coloring. She had had no other urticarial reactions since that episode. Discussion Although there have been no previous reports of contact urticaria from panthenol, contact urticaria from hair conditioners has been reported previously from hydroxy-propyl trimonium hydrolyzed collagen (Crotein Q) (4, 5) and to hydrolyzed proteins (6). Panthenol, as a coen-zyme constitutent derived from b-alanine, could be acting in the same manner as Crotein Q, thus causing …