Hailey-Hailey disease: This genetic (inherited) skin condition causes a painful rash with blister formation in skin folds, such as the armpits, groin, neck, under the breasts, and between the buttocks. The signs and symptoms tend to worsen with sunburn, sweating, and friction (such as tight clothing) in the affected areas. A mutation in a gene known as ATP2C1 causes the condition, and people inherit the condition in an autosomal dominant manner. This means that when one parent has a copy of the mutant gene, the children have a 50% chance of developing the condition. Also known as familial benign pemphigus.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.