Occupational allergic contact dermatitis to marijuana

We report on a 24-year-old female patient who presented to our Department of Dermatology the with eczematous skin lesions. Atopic dermatitis was diagnosed in childhood but she described an exacerbation of the skin findings after starting to work as a medical technical assistant in the laboratory of the criminal police department. A 24-year-old woman presented to our outpatient clinic with severe eczematous skin lesions. Atopic dermatitis has been diagnosed the first time in childhood and improved by early adolescence. In addition, she had a rhinoconjunctivitis allergica with type I sensitization to rye, grasses, mugwort and a diagnosed contact allergy to nickel-containing costume jewellery. The actual eczematous skin lesions began after starting to work as a medical technical assistant in the laboratory of the criminal police department. She presented with macules and papules in the face, neck, shoulders, elbows, wrists and back of the hands, similar distributed as in atopic dermatitis and she described severe itching (8/10 numeric rating scale [NRS]) and sleep disturbance (5/10 NRS). Local therapy with topical corticosteroids (TCS) class II resulted in a short-term improvement only. During her occupation, she had to wash her hands frequently, she used hand disinfection and she was wearing nitrile gloves. The substances she examined mainly included marijuana, 3,4-methylenedioxy-N-methylamphetamine (MDMA) and N-methylamphetamine. We patch tested with standard panel, plant components, disinfectants and rubber series (SmartPractice Europe GmbH, Greven, Germany) as well as the gloves she used at work and marijuana 5% or 10% in petrolatum (pet.). MDMA and N-methylamphetamine were not provided for testing. We saw a double-positive patch test reaction at 48 and 72 h to marijuana 5% and 10% (pet.) and a single-positive patch test reaction to nickel sulfate at 72 h (Figure 1). We diagnosed an allergic contact dermatitis due to type IV sensitization to aerogenic transmitted marijuana with a not previously known but current occupational relevance. The type IV sensitization to nickel sulfate was confirmed. However, this was only relevant in the past, as the patient avoids contact with costume jewellery. The employer took actions as a result to avoid contact with marijuana and in addition we prescribed a local therapy with TCS class II/III followed by topical calcineurin-inhibitors (TCI) which resulted in an improvement of the allergic contact dermatitis. Cannabis (C.) is a hemp plant which belongs to the family Cannabaceae and order Rosales. The three major species are C. sativa, C. indica and C. ruderalis. C. sativa and C. indica are commonly used in industry and for medical and cosmetical purposes. Fibres for the textile industry and for the production of ropes are obtained from the stem, while the cannabinoids Delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are extracted from the resin containing flowers. Marijuana is a drug made from the dried flowers and leaves of the female hemp plant and contains the psychoactive substance THC. CBD is used as food supplements and in cosmetics for example hemp seed oil. Several reports of type I sensitization to cannabis plants (contact urticaria, anaphylaxis) have been published.1-4 Only a few individual case reports exist to date about contact allergic reactions to hemp seed oil with CBD5, 6: For example, a young female patient developed eczema in the areas where she applied C. sativa seed oil. A type IV sensitization was confirmed by patch test and repetitive open application test.6 We were able to show a rare case of an occupational type IV sensitization to aerogenic transmitted marijuana mimicking atopic dermatitis. Another case of airborne allergic contact dermatitis in the facial area due to consumption of medical marijuana was recently published.7 Marijuana is an increasingly consumed drug with possible side effects, type I sensitization and, as shown here, type IV sensitization. An aerogenic transmitted type IV sensitization can be difficult to distinguish from atopic dermatitis. Therefore, a detailed personal and occupational history and a diagnosis with patch test are extremely important for the correct diagnosis. S. Heyne: Writing – original draft; data curation; investigation. J. Steininger: Supervision; investigation. A. Bauer: Writing – review and editing; supervision. Open Access funding enabled and organized by Projekt DEAL. The authors declare no conflicts of interest. The patient gave her written consent for the photos to be taken and published.