Contact Dermatitis From Gum Mastic (Pistacia lentiscus) and Gum Storax (Liquidambar styraciflua) in Mastisol-Allergic Patients.

BACKGROUND

Mastisol Liquid Adhesive is widely used on the skin, especially after surgical procedures. It contains gum mastic, gum storax, methyl salicylate, and ethanol.

OBJECTIVE

The aims of the study were to review our experience patch testing patients allergic to Mastisol and to assess coreacting substances.

METHODS

We identified 18 patients who were allergic to Mastisol. Most of these had a history of postoperative or cardiac electrode dermatitis and underwent patch testing with multiple surgically related substances, including ingredients of Mastisol, compound tincture of benzoin, and fragrance-related ingredients and botanicals.

RESULTS AND

CONCLUSIONS

Among Mastisol-allergic patients, 13 (72%) of 18 were allergic to gum mastic, whereas 7 (44%) of 16 were allergic to gum storax. There was frequent coreactivity with various fragrance-related materials, including Majantol, Styrax benzoin, Myroxylon balsamum, Myroxylon pereirae, propolis, and others. Two gum mastic-allergic patients had positive patch tests with hydroperoxides of linalool and several other linalool-containing essential oils. As gum mastic contains linalool, it may explain some gum mastic reactions. Among patients without a history of postoperative contact dermatitis, 1 (0.4%) of 250 was patch test positive for gum mastic. This patient had allergic contact dermatitis from fragrances, so the gum mastic reaction was likely a true-positive relevant reaction.