A range of conditions can cause these black spots. Obtain a professional diagnosis to ensure appropriate treatment.
In this article, we explore the conditions that cause black spots to form on the scrotum. We also describe accompanying symptoms, how a doctor will determine a diagnosis, and the treatment options available.
Black spots on the scrotum may have many different causes.
Black spots may form on the scrotum temporarily or permanently. The following are some of the most common causes.
Physical injury can damage small blood vessels, causing blood to pool in the tissues. This results in areas of dark, tender skin, known as bruises.
Most bruises clear up within 2 weeks.
Dark or ingrown hair follicles
After removing hair, often by waxing or shaving, new hair may appear darker than before.
If a hair in an early stage of growth becomes trapped beneath the skin, or ingrown, the resulting bump may appear as a dark or discolored spot.
Ingrown hairs can also be painful or tender and swollen.
Pimples and blackheads
These minor skin conditions are caused by mild infection or clogged pores. They are extremely common and may appear as dark spots on the scrotum.
Hyperpigmentation occurs when some areas of skin develop more pigment. This can appear as a variety of skin lesions, such as:
- sun spots
- stretch marks
- age spots
A 2013 study looked at 400 males between the ages of 3 and 91 who received medical attention for genital lesions. Of these, 85.6 percent of cases involved hyperpigmentation.
Hyperpigmentation lesions are generally harmless, and many have no symptoms beyond discoloration of the skin.
This condition causes small blood vessels to widen, resulting in non-cancerous skin lesions that may be dark red or blue.
These lesions tend to have clear edges, and most are:
- 1 millimeter (mm) to 8 mm in size
- raised in a dome-shape
- abnormally thick
- randomly distributed, when they appear on the scrotum
If these lesions cause irritation, or if a person scratches them by accident, scaling, crusting, bleeding, and blood blisters can occur.
The risk of developing these lesions increases greatly with age. At age 16, a boy is estimated to have a 0.6 percent chance of developing this condition on the scrotum. The risk rises to 17 percent for men aged over 70.
These lesions can form on the genitals, inner thighs, or elsewhere in the groin area. They are caused by strains of human papillomavirus (HPV).
Warts can appear as white or skin-colored bumps, and some may resemble cauliflower. However, others may be dark or have darkened center.
Dermatitis refers to chronic inflammation of the skin. The scrotum's skin is very thin, making it easily irritated and inflamed. Exposure to allergens and irritants, especially on a regular basis, can cause scrotal dermatitis.
Itching, scratching, and chafing of inflamed skin can irritate the small blood vessels close to the skin's surface. This can lead to bruising or the appearance of other dark spots.
While a person can have an allergic reaction to almost anything, some chemicals and compounds are more likely to cause dermatitis.
Common causes of external genital dermatitis include:
- clothing dyes
- chemicals in laundry detergents
- spermicides and lubricants
- topical antiseptics and antibiotics
- chafing from underwear or protective sports gear
Less common causes
A complete blood count may be used to diagnose black spots on the scrotum.
A doctor will perform a variety of tests to determine the cause of spots on the scrotum. They may be able to make a diagnosis based on a physical examination alone, but more complicated tests may be required.
A doctor might also refer a person to a dermatologist, who specializes in skin conditions. This will depend on a person's symptoms and other factors specific to an individual.
Tests often used to diagnose black spots on the scrotum include:
- a complete blood count
- tests for liver and kidney function
- screenings for STIs, such as HIV and hepatitis B and C
- an erythrocyte sedimentation rate test, which can indicate the extent of inflammation
- a biopsy, which involves taking a sample of skin to study
- an ultrasound of the lower abdomen and genital area
Depending on the cause, a range of procedures, medications and home remedies can reduce or eliminate black spots on the scrotum.
Most bruises respond well when a person applies an ice pack or mild heat to the area. Some over-the-counter creams may also ease pain and inflammation.
Dark or ingrown hair follicles
There is no medical need to treat dark hair follicles, though some may choose to lighten them for cosmetic purposes.
Ingrown hairs can usually be eliminated by exfoliating. This will remove the top layer of dead skin cells and help to prevent hairs from becoming trapped.
Pimples or blackheads
The best way to treat most pimples and blackheads is to keep the area exfoliated, clean, and dry.
Larger pimples and blackheads may respond well to a warm compress. This will gently encourage blood flow in the area, which can help the bump to burst and resolve.
In most cases, there is no need to treat areas of hyperpigmentation.
A person may choose to have prominent lesions, such as large or irregular moles, surgically removed, especially if they are causing discomfort.
See a doctor if a mole has irregular borders or grows rapidly, as this can indicate cancer.
Because they are usually harmless, there is usually no need to treat angiokeratoma lesions. A person may have them surgically removed if the location or size causes discomfort, or for cosmetic reasons.
A doctor will often take a biopsy of a lesion to ensure that it is not cancerous, particularly in cases of removal.
Techniques commonly used to remove angiokeratoma lesions include laser therapy and excision or scraping, usually with a scalpel. A person may instead have their lesion frozen off or burned with an electric current.
The best way to treat scrotal dermatitis is to avoid exposure to the allergen or irritant causing the inflammation.
To reduce symptoms, wash the skin gently with mild soap and lukewarm water several times a day. Taking a long bath with Epsom salts or oatmeal may also help.
If the dermatitis is severe or lasting, a doctor may prescribe a steroid cream to reduce itching.
The treatment of this STI usually depends on the size, extent, and location of lesions, as well as the amount of concern a person may have.
Over-the-counter wart treatments are not safe to use on genital warts.
While there is currently no cure for genital warts, a person may choose to have them removed.
Common methods of removing genital warts include:
- freezing them off
- burning them with a cauterizing device
- cutting or scraping them away with a scalpel
- applying prescription creams and chemical preparations designed to separate warts from the skin
Removal usually reduces symptoms and can lower the risk of infecting a sexual partner.
The Gardasil vaccine can provide immunity against two types of HPV virus that together cause around 90 percent of cases of genital warts in the U.S.
When to see a doctor
If the black spots cause pain or discomfort, discuss them with a doctor.
Talk to a doctor or nurse if black spots on the scrotum are causing concern, pain, or discomfort. Also, seek advice if these spots are changing for no apparent reason.
For most common causes of these black spots, simple treatments can reduce or eliminate symptoms.
While black spots on the scrotum very rarely indicate cancer or HIV, a medical professional should rule out any possible link to a severe condition whenever a black skin lesion appears on the body.
In most cases, black spots on the scrotum are harmless, and any associated discomfort will be mild.
See a doctor if these spots change, have an unclear cause, or lead to long-term pain or discomfort.