What's causing the itch down there?

When a man feels itchy down there, the itch is commonly due to a rash caused by inflammatory skin diseases, fungi, lice, or a viral infection. While viral infection and lice infestation are usually sexually transmitted, the other skin conditions have non-sexual causes.

However, whatever the cause of this itch, it is always advisable to seek medical attention instead of trying to treat the problem with over-the-counter skin creams.

Here’s a rundown of the ailments that can explain why a man’s privates – especially the pubic area and penis – can feel uncomfortably itchy.

Types of itch that can affect the pubic area

  • Pubic lice (crabs): These lice are tiny parasites that attach themselves to the pubic hair of humans (known as the host). “Crabs are often spread by sexual contact with an infected person,” says Dr ​Pang Shiu Ming, Senior C​onsult​ant, Department of Dermatology, Singapore General Hospital (SGH), a member of the SingHealth group. “The main symptoms are itching in the pubic area, as well as bloodstains and black dots which are the faeces of the crabs on the underwear.
  • Folliculitis affects the pubic area but it is usually more painful than itchy.
  • Molluscum contagiosum is a viral infection that looks like tiny pearls. This sexually transmitted infection (STI) may also sometimes appear on the shaft of the penis

Types of itch that can affect the shaft of the penis

  • Genital herpes: A sexually transmitted infection caused by the herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2). During an outbreak, blisters can appear.
  • Lichen nitidus consists of tiny papules on the shaft of the penis which may be itchy. It is not a STI.

Types of itch that can affect the tip of the penis (glans penis)

  • Genital herpes very often affects the glans penis and the foreskin of the penis.
  • Candidiasis of the glans penis is a fungal infection that may be the first presenting symptom of diabetes mellitus in men.
  • Genital warts are a STI caused by a viral infection. The warts often appear on the glans penis and the foreskin and may be associated with discharge that causes itching. The warts may also appear on the shaft of the penis and in the pubic area.
  • Lichen planus, psoriasis and strong seborrhoeic dermatitis are non-STIs that may affect the tip of the penis. Therefore, not every itchy rash on the penis is a STI.

Other skin conditions​

These conditions affect more than one part of the male genitalia.

  • Scabies: This is an infestation of the skin with the microscopic mite Sarcoptes scabiei. Dr Pang explains: “It is caused by skin-to-skin contact in crowded conditions like hospitals, institutions, child-care facilities, and nursing homes. It is characterised by severe itching of the infected skin regions, like the scrotum, buttocks and penis. The rest of the body, particularly the finger webs, the umbilicus and the armpits, is usually affected as well.”
  • Contact dermatitis: This is caused by direct contact with an irritating substance or allergen. Examples are medicated soaps, bubble baths, urine and rubber products. “Affected persons feel discomfort at first. Then there might be a rash or itching in the affected area,” explains Dr Pang. “Actually, this condition can be more painful than itchy, especially when it affects the scrotal skin.”

Contact dermatitis (due to wearing a condom) may produce an itchy rash on the glans penis. The rash may spread to the shaft of the penis, the scrotal skin and the groin. It may also cause consort contact dermatitis of the vulval region in the female partner. Similarly, use of spermicide by the female partner may give rise to consort contact dermatitis in the male partner.

An itch down there may or may not be a STI, but in all cases, it’s best to consult a doctor and seek a proper medical diagnosis instead of self-medicating.

Read on for an overview of the main causes of testicular itch that affects the scrotal sac and groin, as well as tips to cope with the itching.

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Ref: T12