Genital friction blister - or something else, like
herpes or an allergic or fungal rash?

• "Intraepidermal" means the burn forms in the top, epidermal, layer of the skin.
• Skin has multiple layers: the stratum corneum, epidermis, and dermis. The epidermis is part of the top layer of skin.

• The degree of skin damage depends on the force of the friction.

• Shaft of the penis (male)
• Head of the penis (male)
• Pubic area (male and female)
• Vagina entrance (female)
• Vulvar area (female)

• Vigorous masturbation
• Intense, prolonged intercourse
• Wearing tight-fitting clothing during exercise
• Vigorous drying with a coarse towel after a shower

1.  The area that was rubbed will become red and swollen and begin burning almost immediately.

2.  Progression to a blister can happen within hours. The blister is usually very tense, with clear fluid inside it. (But friction blisters rarely form in the genital area.)

3.  The blister might rupture immediately after it forms (if it's located very close to the surface), or it might last for a few days (if it forms deeper in the skin).

4.  It might take one week for a burn or blister to get better without scarring.

• History
• • The patient should be asked about recent rubbing trauma.
• Symptoms
• • Immediate pain following friction trauma is likely.
• Visual exam of the area

• What caused the rash, or what event preceded the rash's appearance?
• How much time passed after the suspected cause before symptoms appeared?
• Did nonspecific systemic symptoms precede the rash's appearance (i.e., during a prodrome period)?

Herpes

Friction burn

Herpes

Friction burn

• Herpes usually presents with systemic symptoms and signs, such as fever, lymph node enlargement, overall weakness, and flu-like symptoms, that precede the appearance of the rash.
• Friction burn rash, on the other hand, does not have any preceding systemic symptoms.

• The location of the rash
• The rash's appearance and progression

Herpes

Herpes lesions usually appear on the part of the skin that borders the mucosa (the herpes virus prefers thin, moist skin areas):

Friction burn

Friction burn can affect any area that is commonly rubbed (usually protruding or commonly used surfaces), regardless of skin thickness:

Herpes skin changes

Herpes rash goes through the following stages:

Friction burn skin appearance

• History of the rash
• Rash location and size
• Symptoms
• The rash's appearance during physical examination

• Intense sex or masturbation
• Wearing tight underwear

• After using a new skin care product, new condom, new lubricant, etc.
• A person can develop an allergic reaction to a product they've used for a long time, but an allergic reaction to a new product is more common.

Friction burn might hurt and show up immediately or a few hours after the event.

Unlike friction burn, an allergic skin rash is usually a delayed hypersensitivity reaction that can take 24 to 72 hours to appear.

Friction burn rash usually appears on protuberant areas (glans of the penis) or the area that was rubbed (the shaft of the penis or the vaginal opening). Friction burn rash is small in size.

• Allergic rash can affect any skin area that came into contact with the trigger.
• The affected area is usually much bigger. It is very rare to see one small spot of allergic rash.

• The main symptom of friction burn is pain over the area that worsens when it's touched.

• The main symptom of allergic rash is itch. Burning can follow the itch, but itch is still the predominant symptom.

• Visible superficial skin damage (the top skin layer is gone)
• Redness
• Minimal swelling
• Very sensitive to touch (touch triggers more discomfort)

• Hot to the touch
• Very red
• Significant swelling
• Scaling and thickening of the skin can be visible with prolonged exposure to allergy trigger.

• History of the rash
• Rash location and size
• Symptoms
• The rash's appearance during physical examination

• Intense sex or masturbation
• Wearing tight underwear

• Poor hygiene
• Being overweight
• Hot, humid weather
• Intense exercise with sweating, with the area remaining wet for some time

Friction burn rash might hurt and become visible immediately or a few hours after the event that caused it.

Fungal rash usually takes about 4 days to appear on the genital area, but may take up to 10 days.

Friction burn rash usually appears on protuberant areas (glans of the penis) or the area that was rubbed (the shaft of the penis or the vaginal opening). Friction burn rash is small in size.

• Allergic rash can affect any skin area that came into contact with the trigger.
• The affected area is usually much bigger. It is very rare to see one small spot of allergic rash.

Friction burn rash usually appears on protruding surfaces (glans of the penis) or an area that was rubbed (penis shaft or vaginal opening) during sex or exercise. Friction burn rash is small in size.

• Fungal rash usually occurs in warm, moist areas (e.g., uncircumcised penis head, skin fold areas).
• The affected area is usually much bigger, affecting the entire moist area, that with friction burn rash.
• Fungal rash is usually one-sided (even when both sides get wet).

• The main symptom of friction burn is pain over the area that is aggravated by touch.

• The main symptom of fungal rash is a mild itch.

Friction burn rash usually looks like superficial skin damage-red, minimally swollen, and very sensitive to the touch.

• Fungal rash inflammation is more intense and for that reason very red.
• The borders of the rash are well defined (clearly separate from normal skin).
• At the outside borders of the rash, the skin can be scaly.