One alternative hygienic measure in the treatment of atopic dermatitis syndrome is the use of emollient substances. As well as having emollient properties, colloidal suspensions containing oat extract also have anti-itching and anti-inflammatory effects ( 1,2 ). In recent years, several cases of sensitization to oat preparations have been reported, chiefly in the form of allergic contact dermatitis ( 3,4 ).
This case involves a 7-year-old girl with history of IgE-mediated allergic rhinoconjunctivitis, allergic asthma, and atopic dermatitis syndrome from the age of 3 years, ×under suitable clinical control. After bathing, oat cream was applied to her arms and trunk; after 15 min she presented swollen lesions where the cream had been applied. These lesions did not spread to other locations, nor were there any systemic symptoms. The symptoms disappeared in less than 1 hour without treatment. Subsequently, this child has not used creams or lotions containing oats, and has tolerated several moisturizing products without any problems. She presents no problems when she eats foods containing oats or other cereals, although she has been advised to avoid eating oats.
The girl was subjected to skin tests using common pneumoallergens and foods (CBF Leti, Madrid, Spain), including cereals and the standard European battery of contact agents. This study included an open patch test according to von Krogh and Maibach (5) using the cream discussed above; 10 checks were performed, 5 topical and 5 nontopical. Specific IgE (Pharmacia Diagnostics, Uppsala, Sweden) was detected for oats and other cereals.
The results of the skin tests were positive for grass, rice and oat pollens, and were negative for the other pneumoallergens and foods. The open patch test was positive, and swollen lesions appeared on the right forearm 10 min after the cream was applied. These symptoms disappeared 30 min after administration of oral cetirizine. The checks were negative. The result for oat-specific IgE was positive, at 0.76 kU/l, and negative for the other cereals.
We present a case of allergic contact urticaria (6) due to a colloidal suspension of oats that was probably IgE-mediated in origin, diagnosed using the open patch test, a positive skin test, and the demonstration of oat-specific IgE. Allergic contact urticaria and/or dermatitis caused by oat extract are not reported as frequently as might be expected. Nevertheless, Pigatto et al. (3) carried out a study on children with atopic dermatitis syndrome and healthy control individuals with the aim of evaluating the frequency of sensitization to colloidal suspensions of oats and rice. They found no cases of contact sensitization, and showed the existence of irritation reactions in tests performed on the skin with readings after 48 h. This study did not show a higher number of cases of sensitization to oat preparations, and therefore supports their safety.
Riboldi et al. (4) reported three cases of atopic eczema syndrome in children, aggravated by sensitization to oat extract. This was shown by a positive skin contact test and positive specific IgE using RAST. None of the three patients presented contact urticaria as a symptom of this aggravation.
Sensitization to oats, in the form of allergic contact dermatitis or urticaria, must be ruled out – particularly when patients mention cutaneous symptoms, or the aggravation of existing ones after application of products that contain oats (7). Although sensitization to oat preparations does occur, they may be considered safe to use, and they represent another therapeutic option for atopic dermatitis syndrome.
Accepted for publication 8 August 2002
Allergy 2002: 57:1215
Copyright © Blackwell Munksgaard 2002