A CASE OF ALLERGIC CONTACT DERMATITIS DUE TO SODIUM CARBOXYMETHYL CELLULOSE

Abstract

A case which had been accompanied by eczematous eruptions on the hands since 8 years ago was examined and it was clarified that the cause of the eruptions was allergic contact dermatitis due to sodium carboxymethyl cellulose (CMC, sodium cellulose glycolate) with which he had usually been in contact to make cakes as a baker.
The patient was a 39-year-old Japanese male who had been working as a baker for about 14 years. He had been complaining of diffuse erythematous squamous eruptions with considerable itching on the hands, particularly on the palm for 8 years. He had undergone various treatments with frequent recurrence. Laboratory tests gave no abnormal results. Histopathological examination of the right palm with erythematous squamous lesions showed hyperkeratosis with parakeratosis, acanthosis, spongiosis and intracellular edema in the epidermis, and perivascular lymphoid infiltration in the upper dermis. From the history, and clinical and histological features, chronic contact dermatitis was suggested. Close patch tests were carried out for 48 hours with CMC and milk powder suspected as the sensitizers, out of the substances with which he was usually in contact to make cakes as a baker, at 2 per cent concentration each in petrolatum. Patch tests with CMC showed positive results which continued positive even 48 hours after the patch test. It was diagnosed as allergic contact dermatitis due to sodium carboxymethyl cellulose.
CMC is an anionic cellulose polymer and synthesized from purified cellulose and sodium chloroacetate. CMC is generally used to enhance the viscosity in the foods, cosmetics and so on. CMC is also used as a bulk laxative and a gastric antacid. The allowable limit for the use of CMC in Japan is set as follows : total amount of CMC not to exceed 2 per cent by weight of finished food. Food grade CMC is generally recognized as safe. Skin irritation due to CMC has not yet been observed. However, it was suggested that a polymer like CMC was able to act as an allergen from the examination results of the present case.