Inverse Psoriasis

What inverse psoriasis looks like

Psoriasis is an immune-driven skin condition that speeds up skin cell turnover. In most body areas this produces thick, raised plaques with silvery scale. In skin folds, warmth, moisture and rubbing change the picture:

• Smooth, shiny, red or dark-red patches with sharp borders
• Little or no scale
• Patches often mirror each other on both sides of a fold
• Soreness, itching or burning, worsened by sweat and friction
• Painful splits (fissures) in the crease
• On darker skin, patches may look purple, dark brown or gray rather than red

Most people with inverse psoriasis also have typical plaques elsewhere, or nail changes such as pitting. Looking for these clues helps confirm the diagnosis. Read more about the condition in general on our psoriasis page.

Common locations

• Armpits
• Groin and inner thighs
• Under the breasts
• Between the buttocks (the natal cleft), often with a pink, cracked area at the top
• Genitals: vulva, penis and scrotum. Genital psoriasis affects a large share of people with psoriasis at some point.
• Belly folds and the navel
• Behind the ears

What triggers inverse psoriasis

• Friction and sweat: tight clothing, exercise, hot weather
• Overweight and obesity: deeper folds create more moisture and rubbing
• Skin infection: yeast and bacteria in the folds can trigger flares (the Koebner response)
• Stress, smoking and heavy alcohol use
• Certain medicines, such as lithium, beta-blockers and stopping oral steroids suddenly

Inverse psoriasis vs similar rashes

These conditions can coexist. Yeast often settles on inverse psoriasis, so treatment sometimes targets both.

How it is diagnosed

A dermatologist usually diagnoses inverse psoriasis by its appearance and by finding psoriasis elsewhere. Other tests:

• Skin scraping for fungus or yeast if infection is possible
• Swab for bacteria if the area is weeping or crusted
• Wood's lamp to exclude erythrasma
• Skin biopsy rarely, if the diagnosis is uncertain

Treatment

Skin in folds is thin and absorbs medicines more easily, so strong steroid creams used elsewhere on the body can cause thinning, stretch marks and broken blood vessels here. Treatment is adapted accordingly.

Topical treatments

• Low- to mid-potency steroid creams or ointments (such as hydrocortisone or desonide) for short courses, often 1 to 2 weeks, then on a few days a week to keep flares down.
• Calcineurin inhibitors (tacrolimus ointment, pimecrolimus cream): steroid-free, safe for longer use in folds and on genitals. Used off-label in psoriasis. They may sting at first.
• Vitamin D analogues such as calcipotriene: effective, but can irritate thin skin, so they are often combined with or alternated with a steroid.
• Newer non-steroid creams: roflumilast cream (approved for plaque psoriasis, including skin folds) and tapinarof cream do not thin the skin and can be used for longer periods.
• Combined creams containing a mild steroid with an antifungal, when yeast is also present.

Phototherapy

Folds are hard to reach with light treatment, so phototherapy is less useful for inverse psoriasis alone. It may help if psoriasis is widespread.

Systemic and biologic treatment

For severe, persistent or genital disease that affects quality of life, or when psoriasis is extensive, dermatologists may recommend:

• oral treatments: apremilast, deucravacitinib, methotrexate
• biologic injections that block IL-17, IL-23 or TNF. Several, including ixekizumab, have been studied specifically in genital psoriasis and work well.

Daily care

• Wear loose, breathable cotton or moisture-wicking clothing.
• Wash with a gentle, fragrance-free cleanser, rinse well and pat dry.
• Use a thin layer of a barrier ointment, such as zinc oxide or petroleum jelly, before exercise.
• Place a soft cotton cloth under the breasts or in belly folds to absorb moisture.
• Avoid scented soaps, wipes and bubble baths, especially on the genitals.
• Losing weight, if you are overweight, reduces fold friction and often improves psoriasis in general.

Outlook

Inverse psoriasis is long-term and tends to flare and settle. Most people control it with fold-safe topical treatments and good skin care. Psoriasis is linked to psoriatic arthritis, heart disease and metabolic problems, so regular checkups with blood pressure, weight and cholesterol checks are recommended.

Frequently asked questions

What does inverse psoriasis look like?

It looks like smooth, shiny, sharply outlined red patches in skin folds such as the armpits, groin, under the breasts and between the buttocks. There is usually little or no scale. On darker skin it can look purple or dark brown. The skin may crack in the crease.

How do you tell inverse psoriasis from a yeast infection?

Yeast infections usually have small red spots or pustules beyond the main patch and improve within 1 to 2 weeks of antifungal cream. Inverse psoriasis has a sharp edge, no satellite spots, does not respond to antifungals, and often comes with psoriasis elsewhere or nail pitting. The two can occur together.

Can I use steroid cream on inverse psoriasis?

Yes, but usually a low-strength steroid for a short time, because skin in folds is thin and absorbs more medicine. Strong steroids used for long periods can thin the skin and cause stretch marks. Steroid-free options, such as tacrolimus, roflumilast or tapinarof, are often used for maintenance.

Is inverse psoriasis contagious?

No. Psoriasis is an immune condition and cannot spread through touch, sex, towels or swimming pools. Infections like yeast that sometimes settle on psoriasis patches can spread, which is one reason a doctor's diagnosis is useful.

Does genital psoriasis affect sex?

It can cause soreness, itching and embarrassment, and friction may trigger flares. Using a lubricant, washing gently afterward, and treating flares beforehand helps. Condoms are safe to use. Psoriasis is not a sexually transmitted infection and does not affect fertility.