Smegma, a transliteration of the Greek wor σμήγμα for sebum, is a combination of exfoliated (shed) epithelial cells, transudated skin oils, and moisture, and can accumulate under the foreskin of males and within the vulva of females. It has a characteristic strong odor. Smegma is common to all mammals, male and female. Mycobacterium smegmatis is the characteristic bacterium involved in smegma production, and is generally thought to form smegma from epidermal secretions.