Inverse Psoriasis

Overview: What Is Inverse Psoriasis?

Between 21-30 percent of people living with psoriasis develop inverse psoriasis. [1] Inverse psoriasis is also called intertriginous psoriasis or flexural psoriasis. Inverse psoriasis may start at any age, even as young as infants in the form of psoriatic diaper rash. [2] Inverse psoriasis is more common in overweight people and those with deep skin folds. [3]

Psoriasis is a chronic disease that is caused by an overactive immune system and is associated with inflammation throughout the body. Symptoms may resolve and recur throughout a person's life.

Inverse psoriasis in an armpit of a white person.

Inverse psoriasis on the armpit, arm, and chest of a white person.

Symptoms

Inverse psoriasis appears on skin of color as lesions of purple-ish, brown, or darker than the surrounding skin, in body folds. On Caucasian skin, it appears as bright red lesions in body folds. It may appear smooth and shiny. Many people with inverse psoriasis have another type of psoriasis elsewhere on the body at the same time such as plaque psoriasis.

Inverse psoriasis affects skin folds in the body, such as underarms, under breasts, in the genital area, the space between the buttocks, and under the buttocks. Rubbing and sweating can further irritate inverse psoriasis because of its location in skin folds and tender areas. It can cause severe itching and pain. It usually does not have the scale that comes with plaque psoriasis because of the moist environment. [3] Sometimes, inverse psoriasis leads to fungal infections in certain areas. [4]

Psoriasis on the skin folds is considered a high-impact site, which can have an increased negative impact on quality of life, regardless of the total area affected by psoriasis.

Causes and Triggers

The cause of psoriasis is not fully understood. Psoriasis lesions occur because the overactive immune system speeds up skin cell growth. Normal skin cells completely grow and shed (fall off) in a month. With psoriasis, skin cells do this in only three or four days. Instead of shedding, the skin cells pile up on the surface of the skin.

Inflammation caused by psoriasis can impact other organs and tissues in the body. People with psoriasis may also experience related health conditions. One in three people with psoriasis may also develop psoriatic arthritis.

Common triggers for inverse psoriasis include:

Certain medicines
Starting and stopping medicines
Infections
Injury to the skin
Stress
Tobacco or alcohol use
Friction on deep skin folds

Learn more about triggers and flares by requesting a free Flare Guide and Symptom Tracker.

Diagnosis

A health care provider will take several factors into consideration when making a diagnosis for psoriasis, including:

The appearance of the skin. Discolored lesions may appear smooth and shiny.
The location of psoriasis. Inverse psoriasis lesions appear in skin folds.
Itch of the skin. This is a common symptom of psoriasis.
A skin biopsy (the removal of a small piece of skin to be looked at under a microscope). A biopsy may also be done to determine if it is psoriasis or another skin condition.

Inverse psoriasis on skin of color may be misdiagnosed as intertrigo or other fungal infections, as these conditions also present as itchy and inflamed areas. [5]

Treatment & Management

Although there is no cure, there are more effective psoriasis treatments today than ever before. Treating psoriasis can help improve symptoms as well as lower the risk of developing psoriasis comorbidities such as psoriatic arthritis, heart disease, obesity, diabetes, and depression.

Treatments for psoriasis include:

Topicals, including over-the-counter topicals, topical steroids, and topical non-steroids
Phototherapy
Systemics, including oral, biologic, and biosimilar treatments

Because skin folds can be prone to yeast and fungal infections, your health care provider may prescribe a combination of treatments. Do not occlude (cover) skin folds unless directed by a health care provider. To keep the lesions in skin folds dry and to lower the risk of fungal infection, your provider may recommend the use of powders to dry the moist lesions.

Over-the-Counter Products

Over-the-counter (OTC) products may help manage symptoms if you have mild plaque psoriasis. If you are looking for OTC products to try, check out NPF's Seal of Recognition program. These products have been created or are intended to be non-irritating and safe for people with psoriasis.

Prevention

There is no known way to prevent the onset of psoriasis, however, there are many ways that you can manage your triggers to reduce flares.

Outlook/Prognosis

Psoriatic disease is lifelong, and symptoms may resolve and recur throughout the lifetime.

While there is no cure for psoriasis, treatments today are more effective than ever before and research into new treatments, as well as a cure, is ongoing. Treating psoriasis can help improve symptoms and may decrease the associated inflammation that can lead to psoriasis comorbidities such as psoriatic arthritis, heart disease, and depression.

Why treat psoriasis?

Additional Resources

A Black woman in a white tanktop holds her hand near her armpit.

Inverse Psoriasis Uncovered

Dr. Jeffrey Cohen discusses typical symptoms and sites of inverse psoriasis, other potential diseases, risk factors for psoriatic arthritis, and treatments.

Listen to the podcast

Psoriasis Simplified

Explore the NPF Care Path and take the first step toward getting care and living your healthiest life.

Take the next step

Flaring Up Down Below with Psoriasis

Relief from inverse and genital psoriasis starts with having an honest conversation with your health care provider.

Inverse Psoriasis Fact Sheet

Learn about symptoms, triggers, and treatment options for inverse psoriasis.

Get your fact sheet

References

Merola, J. F., Li, T., Li, W. Q., Cho, E., & Qureshi, A. A. (2016). Prevalence of psoriasis phenotypes among men and women in the USA. Clin Exp Dermatol, 41(5), 486-489. doi:10.1111/ced.12805
Morris A, Rogers M, Fischer G, Williams K. Childhood psoriasis: a clinical review of 1262 cases. Pediatr Dermatol. 2001;18(3):188-198. doi:10.1046/j.1525-1470.2001.018003188.x
Khosravi H, Siegel MP, Van Voorhees AS, Merola JF. Treatment of Inverse/Intertriginous Psoriasis: Updated Guidelines from the Medical Board of the National Psoriasis Foundation. J Drugs Dermatol. 2017;16(8):760-766. PMID: 28809991
Dopytalska K, Sobolewski P, Błaszczak A, Szymańska E, Walecka I. Psoriasis in special localizations. Reumatologia. 2018;56(6):392-398. doi:10.5114/reum.2018.80718
S. Desai, M.D., FAAD, personal communication, 4/28/21.

Last updated on 03/26/2025 by the National Psoriasis Foundation.