Researchers found that mice with damaged CLOCK genes, which govern the body's natural rhythms, such as the sleep-wake cycle, developed severe contact hypersensitivity.
Mice with the faulty genes had severe inflammation, ear swelling and high levels of serum immunoglobulin E and mast cells - which promote contact allergy - compared with normal mice.
Corticosterone, which protects against such immune response, was lower among mutated mice.
The study authors said the findings suggested a role for CLOCK mutations in promoting an immune response that exacerbates contact hypersensitivity.
Takita E, Yokota S, Tahara Y et al. Br J Dermatol 2013; 168: 39-46