Acne appears to be strongly inherited with 81% of the variation in the population explained by genetics.[15] Studies performed in affected twins and first-degree relatives further demonstrate the strongly inherited nature of acne.[2][15] Acne susceptibility is likely due to the influence of multiple genes, as the disease does not follow a classic (Mendelian) inheritance pattern. Several gene candidates have been proposed including certain variations in tumor necrosis factor-alpha (TNF-alpha), IL-1 alpha, and CYP1A1 genes, among others.[19] The 308 G/A single nucleotide polymorphism variation in the gene for TNF is associated with an increased risk for acne.[40] Acne can be a feature of rare genetic disorders such as Apert's syndrome.[15] Severe acne may be associated with XYY syndrome.[41]

Pimples are raised red spots with a white center that develop when blocked hair follicles become inflamed or infected with bacteria. Blockages and inflammation that develop deep inside hair follicles produce cystlike lumps beneath the surface of your skin. Other pores in your skin, which are the openings of the sweat glands, aren't usually involved in acne.