Three types of acrochordons exist. Small, furrowed papules of approximately 1-2 mm in width and height, located mostly on the neck and axillae. Single or multiple filiform lesions of approximately 2 mm in width and 5 mm length occurring elsewhere in the body. Large, pedunculated tumor or nevoid, baglike, soft fibromas that occur in the lower trunk. Pedunculated lesions may become twisted, infarcted, and fall off spontaneously.
Frequent irritation seems to be an important causative factor, especially in the obese.
An opinion also exists that acrochordons are simply the effect of skin aging with many factors responsible for their development. Whether any infective factors initiate acrochordon growth still is not clear. According to the authors of the study, viral infection should be considered as a pathogenic cofactor. They have been reported to accompany other neoplasms, especially tumors of the gastrointestinal tract and kidneys. It has been suggested that neoplasms produce and release into the circulation growth factors causing acrochordon growth.