There are many individual differences in anal and genital anatomy. Sometimes they may be mistaken for an STI.
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Pearly penile papules are a small ring of white bumps, or skin tags, around the edge of the head of a penis. Pearly papules can be easily confused with warts, but they are not related. They occur naturally in a number of people and are not sexually transmitted or contagious.
A good way to tell pearly papules from warts is that warts are usually hard and scattered over the anus and genitals, with no apparent pattern or uniformity, but pearly papules generally sit in regular, almost straight, lines in a ring around the widest part of the head of the penis. It’s highly unlikely that warts would appear in a similar pattern.
Fordyce spots are in genital glands. They look like very small white dots or lumps that are evenly spread just under the skin of the vulva and the penis (particularly when skin is stretched). In some people they are more visible than others.
Parafrenular glands are located on the underside of the penis below the head. They may appear like two small white lumps sitting opposite each other.
Vitiligo is a relatively common acquired loss of pigmentation of the skin. It affects 1-2% of the population. It causes the skin to lose its pigmentation, causing the skin to become very light. The most common sites of pigmentation loss are around the body folds (including the groin and armpits), around body openings and exposed areas like the face or hands.
Vitiligo is not contagious.