Sebaceous hyperplasia is a disorder of the sebaceous glands in which they become enlarged, producing flesh-colored or yellowish, shiny, often umbilicated bumps. Sebaceous hyperplasia, primarily affecting older patients in high-concentration areas like the face, head, and neck, typically has a 2-4 mm diameter and causes no symptoms. The lesions are often surrounded by telangiectatic blood vessels, also known as "crown vessels," and a central dell, which is in line with the origin of the lesions.

Sebaceous glands are glands located within the skin and are responsible for secreting an oily substance named sebum. They are commonly associated with hair follicles but they can be found in hairless regions of the skin as well. Their secretion lubricates the skin, protecting it from drying out or becoming irritated.

Murine studies suggest topical irritants and carcinogens may contribute to sebaceous hyperplasia development, with immunosuppression with cyclosporin A or HIV infection increasing the likelihood.

Sebaceous hyperplasia is a condition that can be diagnosed clinically but requires a biopsy for confirmation. It shares similarities with folliculosebaceous unit architecture but has larger and expanded sebaceous glands. Identifying sebaceous hyperplasia using dermatoscopy can help identify it from other lesions. The dermoscopic characteristics include "crown vessels" clusters of white or yellow nodules, a distinct asymmetrical milky-white structure called the cumulus sign, and a central umbilication called the "bonbon toffee sign."

Sebaceous hyperplasia treatment involves various techniques like cryotherapy, bichloroacetic acid, shave excision, carbon dioxide laser ablation, electrodessication, erbium/yttrium aluminum garnet laser ablation, and pulsed-dye laser photothermolysis.

Sebaceous hyperplasia primarily affects older patients in areas with high concentrations of sebaceous glands, such as the face, head, and neck. It typically manifests as yellowish-colored skin with small papules that are often surrounded by telangiectatic blood vessels, also known as "crown vessels," and a central dell that is in line with the origin of the lesions, which is a dilated central follicular infundibulum. Most lesions have a diameter of 2-4 mm and cause no symptoms.

Although the etiology is unknown, murine studies have revealed that topical irritants and carcinogens may be involved in the development of sebaceous hyperplasia.

Immunosuppression with cyclosporin A or HIV infection increases the likelihood of developing sebaceous hyperplasia significantly.