Mudi-chood disease is a scaly eruption seen almost exclusively in young women from Kerala, a state in India. The condition arises on the posterior neck and back from skin contact with residual hair oils applied as part of traditional hair grooming methods in the region.

The condition was first described in 1972 and translates to "heat of the hair" from Malayalam, one of the major languages in India. Long black hair is culturally valued in Kerala, and many women apply large amounts of coconut or sesame oil with or without added plant leaves, flowers, seeds, and roots to promote hair growth. Homemade plant-based shampoos are used to wash the hair but do not sufficiently remove the oil, causing the wet, oily hair to rub against the exposed regions of the posterior neck and upper back. When combined with sweat from environmental humidity and heat, the friction, oil, and hidrosis cause follicular vesicopustules that crust and expand, leading to scaly papules and plaques.

The exact pathogenesis is not known. The condition affects predominantly Malayalee women in their teen years and middle-aged Malayalee women from rural backgrounds. College-aged and older Malayalee women are not typically affected because of differences in grooming techniques: they apply less oil, bathe in the evenings, and use commercially available shampoo. Rare cases have been reported from outside of Kerala, and one case has been reported in a male.