Inverse psoriasis, also known as flexural or intertriginous psoriasis, is a rare and painful form of the inflammatory skin disease psoriasis. It typically presents with smooth, shiny, discolored patches — red, purplish, or brown, depending on skin tone — in the armpits, under the breasts, and in the genital and anal areas. The symptoms of inverse psoriasis can resemble those of other conditions, including intertrigo — inflammation caused by areas of skin rubbing together.
Inverse psoriasis can cause very similar symptoms and affect the same areas as intertrigo. In fact, inverse psoriasis may be mistaken for different types of intertrigo. That said, the two are distinct conditions with different underlying causes. If you experience new or worsened symptoms of either skin condition, talk to your health care provider or a dermatologist. They will be able to determine the cause of your symptoms and work with you to find the best ways of managing them.
Inverse psoriasis is one of the rarest forms of psoriasis, affecting just 3 percent to 7 percent of people with the condition. As with other forms of the skin disease, inverse psoriasis is a chronic inflammatory condition that can persist throughout a person’s life. It causes lesions to form in the areas of the body where skin-to-skin contact occurs, such as the armpits, buttocks, and under the breasts. These areas, known as intertriginous areas or skin folds, may rub together, causing irritation and inflammation.
Read more about inverse psoriasis causes, symptoms, and treatments.
Candidal intertrigo (DermNet NZ)
Unlike inverse psoriasis, which results from immune system dysfunction, intertrigo is caused directly by friction between skin folds. It occurs when intertriginous areas rub together, resulting in irritation and discoloration, usually pink, red, or brown. These areas of skin are also prone to trapping moisture, which can cause the skin to break down (become macerated) and lead to secondary fungal or bacterial infections.
Inverse psoriasis may sometimes be mistaken for candidal intertrigo. This condition occurs when a person with intertrigo has developed a secondary infection with the fungus candida — the most common secondary infection seen in intertrigo. The risk of these types of infections is high, as the warm, moist environment found in skin folds serves as a breeding ground for bacteria and fungi.
Inverse psoriasis (DermNet NZ)
Inverse psoriasis typically creates bright red, purplish, or brown lesions that can feel inflamed and painful. The symptoms of inverse psoriasis may be aggravated by warmth, moisture, and friction, as is the case with intertrigo. Common inverse psoriasis signs and symptoms include:
The symptoms of intertrigo may be acute (short-lived and recent), relapsing (come and go repeatedly), or chronic (remain for more than six weeks). Like psoriasis, intertrigo develops in the skin folds. The friction of skin-on-skin contact can lead to discolored, inflamed, or painful patches of skin. These patches may fissure (crack), peel, and begin to wear down (macerate) due to excess moisture. When a bacterial infection occurs, intertrigo may also give off an unpleasant odor.
Like other types of psoriasis, inverse psoriasis is an autoimmune condition. It occurs when an overactive immune system begins attacking healthy skin cells. These misdirected attacks cause skin cell production to speed up dramatically, which creates the painful, discolored patches of skin, scaling, and pustules characteristic of psoriasis.
Scientists believe that inverse psoriasis may be caused by a combination of genetics and environmental factors. According to the American Academy of Dermatology, people who already have plaque psoriasis and are 20 or more pounds overweight may be at greater risk for having inverse psoriasis, as well.
Some factors may also trigger a person to develop the symptoms of inverse psoriasis, including stress, infections, and skin injuries. Fungal infections, like jock itch, can also trigger inverse psoriasis.
Interestingly enough, both infections and skin inflammation can cause a person to develop intertrigo — including inverse psoriasis. As with inverse psoriasis, a number of genetic and environmental factors are believed to play a role in the development of intertrigo. Living in a hot, humid climate (which contributes to the overgrowth of microorganisms on the skin) and experiencing friction from skin-on-skin contact (chafing) can cause a person to develop the condition.
Like inverse psoriasis, the incidence of intertrigo is higher in people who are overweight or obese. Having diabetes, smoking cigarettes, and drinking excessive alcohol can all increase a person’s risk of developing intertrigo — particularly with a secondary infection.
Because the symptoms of inverse psoriasis can mimic those of other skin diseases, it’s often difficult to diagnose. Smooth discolored patches from skin-on-skin friction — particularly in the groin — can be a sign of inverse psoriasis. Other indicators of the autoimmune disease include a family history of psoriasis, psoriatic plaques (lesions) in other areas of the body, and changes to the nails or nail beds.
In order to confirm a diagnosis of inverse psoriasis or intertrigo, a dermatologist will perform a physical exam and visual inspection. If they suspect an infectious form of intertrigo, they will take skin samples to test for the presence of a bacterial or fungal infection.
If you suspect that you may have inverse psoriasis or intertrigo, talk to a licensed dermatologist. They will provide you with an accurate diagnosis and proper treatment.
Because inverse psoriasis is a chronic autoimmune disease, there is no way to eliminate symptoms permanently. However, people with inverse psoriasis can manage their symptoms and improve their quality of life with a number of medical and at-home therapies.
Treatment options for inverse psoriasis include topical medications, biologic drugs, and phototherapy (or light therapy). Topical corticosteroids, such as 1 percent to 2 percent hydrocortisone, are typically first-line therapies for inverse psoriasis.
Treatment for intertrigo will depend upon the cause of the condition and the particular type of infection that has developed, if any. The fungal infection candida may be treated with topical or oral antifungal medications, such as clotrimazole, terbinafine, and itraconazole. Topical or oral antibiotics, such as mupirocin or erythromycin, are used to treat bacterial intertrigo. As with inverse psoriasis, topical steroids can help control inflammatory symptoms in intertrigo.
There are several ways to manage the symptoms of inverse psoriasis and intertrigo at home or with your dermatologist’s help. Dermatologists generally recommend following a regular home-care practice that helps protect skin against irritation and injury — both of which can worsen skin conditions like intertrigo and inverse psoriasis.
Intertrigo, in particular, may resolve when the affected skin is kept consistently clean and dry. Bathing after physical activity and applying antiperspirant products beforehand can help achieve this. Your dermatologist may also recommend wearing loose-fitting clothing to help reduce irritation in both inverse psoriasis and intertrigo.
Skin affected by inverse psoriasis or intertrigo is prone to bacteria and odors. Frequent bathing in warm water using mild, chemical-free cleansers helps manage microbial buildup. Adding emollients such as bath oil or oatmeal to the water can soothe raw, painful skin. If odor continues, your doctor may order a bacterial culture.
Dermatologists recommend moisturizing after bathing, as well as periodically when skin areas feel dry. Eucerin, plain Aquaphor Healing Ointment, and other over-the-counter emollients help reduce chafing and irritation. They can be alternately applied with topical steroids and other medications.
Light, breathable underwear and clothing can help prevent skin irritation and discomfort. Soft, natural fibers such as cotton help prevent moisture from accumulating in the skin folds. Wash clothing in fragrance-free detergent and double rinse to ensure all soap has been removed.
Soft, high-quality toilet paper helps reduce irritation. Wiping the groin area gently but completely keeps genital lesions free of the bacteria in urine and feces, which can cause inverse psoriasis flare-ups.
Itching is one of the most challenging symptoms of inverse psoriasis to manage. However, it is important to address itching, as scratching the affected areas can create skin injuries, triggering flares and leading to infection.
Using over-the-counter anti-itch and cooling lotions — as well as nonsedating antihistamine drugs by day and hydroxyzine at night — can help reduce the need to scratch. Aloe vera and jojoba oil can also soothe itching.
Inverse psoriasis lesions may sometimes exude liquid. Chemical-free baby powder or cornstarch is often recommended to absorb moisture from weepy patches. Before applying these powders, soak up the existing moisture with a tissue to prevent caking and buildup. Castellani’s paint (a solution containing boric acid, phenol, resorcinol, and fuchsin in acetone, alcohol, and water) is an over-the-counter liquid that’s painted onto skin to dry up moist skin fold lesions.
Living with conditions like inverse psoriasis can be challenging. It can help to have a team of others who truly understand. MyPsoriasisTeam is the social network for people with psoriasis and psoriatic arthritis and their loved ones. Here, more than 96,000 members from across the globe come together to discuss life with psoriatic disease.
Have you experienced inverse psoriasis or intertrigo? How has it been managed? Share your story in the comments below or by posting on MyPsoriasisTeam.