Inverse Psoriasis: The Hidden Form of Psoriasis in Skin Folds

Inverse psoriasis is a form of psoriasis that appears in skin folds, such as the armpits, groin, genitals, under the breasts and between the buttocks, as smooth, shiny, sharply bordered red or dark patches with little or no silvery scale. It affects roughly 21 to 30% of people with psoriasis and is often mistaken for a fungal infection or intertrigo, so it is commonly treated with steroid sparing creams chosen for thin, sensitive fold skin.

What Is Inverse Psoriasis?

Inverse psoriasis (also called flexural or intertriginous psoriasis) is a form of psoriasis that shows up where skin touches skin. Unlike the classic thick, silvery plaques that most people associate with psoriasis, inverse psoriasis produces smooth, shiny, red or dark patches that can look completely different from what you would expect [1]. This is why it catches so many people (and even some clinicians) off guard.

The condition gets its name from the fact that it appears in the “inverse” of where plaque psoriasis typically shows up. While plaque psoriasis favors the outer surfaces of elbows and knees, inverse psoriasis hides in the folds and creases of the body [2].

Like every type of psoriasis, the inverse form is a chronic, immune mediated skin disease driven by the IL-23 and IL-17 inflammatory pathways. It is not an infection and it is not contagious. Omland and Gniadecki (2015) describe it as a variant of psoriasis vulgaris (plaque psoriasis) rather than a separate disease, which is why most people with it also have plaques elsewhere [2]. It sits alongside other subtypes such as guttate psoriasis, pustular psoriasis and nail psoriasis.

What Are the Symptoms of Inverse Psoriasis?

The main symptoms of inverse psoriasis are smooth, shiny, well-defined patches in a skin fold that itch, burn or feel sore, especially with sweat and friction. The patches are bright red on lighter skin and brown, purple or gray on darker skin [5]. Cracks (fissures) can form deep in the crease and may bleed or sting.

Symptoms usually get worse with heat, sweating, tight clothing, exercise and rubbing. Many people notice that the rash flares in summer or after a long day of walking. Because the area is hidden, people often live with it for months before mentioning it to a clinician.

Where Does Inverse Psoriasis Appear?

Inverse psoriasis targets areas where skin rubs against skin. The most common locations include:

• Groin and genital area: This is one of the most common and most distressing locations. Genital involvement occurs in up to 63% of psoriasis patients at some point during their disease course [3].
• Armpits (axillae): Smooth, well-defined red patches in the underarm area.
• Under the breasts (inframammary folds): Particularly common in women with larger breasts.
• Between the buttocks (intergluteal cleft): Often extends to the perianal area.
• Behind the ears: A frequently overlooked location.
• Abdominal folds: More common in individuals with higher body weight, where additional skin folds create new intertriginous areas [4].

Many patients with inverse psoriasis also have plaque psoriasis in other locations, which can actually help with diagnosis. If a patient has typical plaques on their elbows and a shiny red rash in their armpits, putting the picture together becomes easier [2].

Inverse psoriasis in the armpit

Inverse psoriasis in the armpit (axillary psoriasis) looks like a smooth, symmetrical, sharply edged red or dark patch that fills the hollow of the underarm. It often stings when deodorant or antiperspirant is applied, and shaving can make it flare through the Koebner effect, in which skin injury triggers new psoriasis. Fragrance in deodorants can also cause contact dermatitis, which is one reason a dermatologist asks about products [8].

Inverse psoriasis under the breasts

Psoriasis under the breasts appears as a glossy red or violet band in the inframammary fold, usually with a crisp edge and a moist surface. A painful split often runs along the deepest part of the crease. Symptoms tend to worsen with heat, sweat and underwire bras. Because candida infection is common in the same fold, a skin scraping is often taken to check for yeast before treatment starts [6].

Genital and groin inverse psoriasis

Genital inverse psoriasis shows up as smooth, well-defined red or dark patches on the vulva, the penis (often the glans in uncircumcised men), the scrotum, the inner thighs or the pubic area. It is usually not scaly here, and it may itch or burn during intercourse. Ryan and colleagues (2015) found that genital psoriasis significantly impairs quality of life and sexual function [3].

Reliable clinical photographs of these areas are best viewed in dermatology atlases and on patient pages from major academic centers, such as those published by the Cleveland Clinic and the American Academy of Dermatology, rather than in unvetted image searches, where fungal rashes and intertrigo are often mislabeled.

How Inverse Psoriasis Looks Different from Plaque Psoriasis

The signature silvery scale of plaque psoriasis is largely absent in inverse psoriasis. The reason is simple: moisture. Skin folds are warm and humid environments. The constant moisture prevents the buildup of the dry, thick scale that characterizes plaque psoriasis [1]. Instead, you see:

• Smooth, glistening patches that may look “glazed”
• Well-defined borders (sharper than you would see with many other rashes)
• Bright red color on lighter skin, or dark brown to violet on darker skin tones
• Possible fissuring (cracking) at the base of skin folds
• A moist or macerated surface rather than a dry, scaly one

On darker skin, inverse psoriasis may present with more subtle color changes, making it even harder to identify without a trained eye [5].

What Causes and Triggers Inverse Psoriasis?

Inverse psoriasis is caused by the same immune and genetic factors as other psoriasis: overactive T cells release inflammatory signals such as IL-17 and IL-23 that speed up skin cell turnover. What makes the folds different is the local environment. Friction, sweat and trapped moisture act as repeated small injuries, and psoriasis tends to appear where skin is injured (the Koebner phenomenon) [2].

Common triggers include:

• Friction and sweat: Exercise, heat, humidity and tight or synthetic clothing.
• Higher body weight: Jensen and Skov (2016) link obesity with more severe psoriasis and more skin folds for it to occupy [4].
• Infections: Yeast and bacterial overgrowth in a fold can aggravate an existing patch [7].
• Irritants: Shaving, fragranced deodorants, wipes and harsh soaps.
• General psoriasis triggers: Stress, smoking, alcohol and some medicines, as reviewed in our psoriasis guide.

Why Inverse Psoriasis Gets Misdiagnosed

Inverse psoriasis is one of the most commonly misdiagnosed forms of psoriasis. The three conditions it gets confused with most often are:

Fungal Infections (Tinea Cruris, Candidiasis)

A smooth red rash in the groin or skin folds immediately makes many clinicians think of a fungal infection. The difference is that fungal rashes tend to have a scaly, advancing border with central clearing, while inverse psoriasis is more uniformly red with sharply defined, non-advancing borders [6]. Candidal infections also tend to have satellite pustules (small pus-filled bumps) scattered around the main rash, which inverse psoriasis does not produce. Complicating matters, fungal co-infection can occur alongside inverse psoriasis because the warm, moist environment favors fungal growth [7].

Intertrigo

Intertrigo is inflammation caused by skin-on-skin friction and moisture. It can look very similar to inverse psoriasis, especially in its early stages. The key difference is that intertrigo is typically less well-defined and more symmetrical within the fold, while inverse psoriasis has those characteristic sharp borders [6].

Contact Dermatitis

Allergic or irritant contact dermatitis in the groin or underarm can mimic inverse psoriasis. A detailed history about exposure to new products (deodorants, laundry detergents, personal care items) can help differentiate the two [8].

If there is diagnostic uncertainty, a skin biopsy can confirm psoriasis. A KOH preparation or fungal culture can rule in or rule out concurrent fungal infection [7].

Other conditions a dermatologist may consider include seborrheic dermatitis, erythrasma, Hailey-Hailey disease and eczema. Our comparison of psoriasis and eczema covers how those two differ in more detail.

Treatment Challenges: Why Skin Folds Need Special Care

Treating inverse psoriasis is not the same as treating plaque psoriasis on the elbows or knees. The skin in body folds is thinner, more permeable, and naturally occluded (sealed by the fold above it). This creates two problems:

1. Higher drug absorption: Topical medications absorb more readily through thin, occluded skin. A mid-potency steroid applied to the groin can have the same effect as a superpotent steroid on the forearm [9].
2. Greater risk of side effects: The increased absorption means that steroid side effects (skin thinning, striae, telangiectasia) happen faster and more severely in skin folds. Striae in the groin from topical steroids are often permanent [10].

Treatment Options for Inverse Psoriasis

Inverse psoriasis is usually treated first with gentle topical medicines that suit thin fold skin, then with systemic or biologic therapy if it is severe or part of more widespread psoriasis. The National Psoriasis Foundation Medical Board recommended low-potency steroids, calcineurin inhibitors and vitamin D analogs as the core topical options for intertriginous psoriasis (Kalb and colleagues, 2009) [6]. The broader range of options is covered in our psoriasis treatment guide.

Topical Calcineurin Inhibitors (First-Line for Many Dermatologists)

Tacrolimus ointment and pimecrolimus cream are anti-inflammatory medications that do not cause skin thinning. This makes them particularly valuable for inverse psoriasis. Studies show that tacrolimus 0.1% ointment applied twice daily can produce significant improvement in genital and intertriginous psoriasis within 8 weeks [11]. The main side effect is a burning sensation on application, which usually fades after a few days of use.

Both drugs are FDA approved for atopic dermatitis, so using them for psoriasis is off label. That is common and accepted dermatology practice, but it can affect insurance coverage, which is worth asking about at the pharmacy counter.

Low-Potency Topical Corticosteroids

When steroids are used in skin folds, the rule is to use the lowest effective potency for the shortest possible time. Hydrocortisone 1% or desonide 0.05% are appropriate choices. Some dermatologists use a “weekend therapy” approach, where the steroid is applied only on weekends to maintain control while minimizing side effects, alternating with a calcineurin inhibitor on weekdays [10].

Topical Vitamin D Analogs

Calcipotriol (calcipotriene) can be used in skin folds, though it may cause irritation in some patients. The combination of calcipotriol with a low-potency steroid can improve efficacy while limiting steroid exposure [12].

Topical PDE4 Inhibitors

Roflumilast cream 0.3%, approved for plaque psoriasis, has shown particular promise for intertriginous areas. Clinical trials demonstrated significant clearance of inverse psoriasis lesions, and because it is not a steroid, it can be used long-term in sensitive areas without the risk of skin atrophy [13].

The DERMIS-1 and DERMIS-2 trials reported by Lebwohl and colleagues in JAMA (2022) enrolled adults with plaque psoriasis, including patients with intertriginous involvement, and tested once daily roflumilast against a vehicle cream [13]. Tapinarof cream, a non-steroid aryl hydrocarbon receptor agonist approved for plaque psoriasis in 2022, is another option some dermatologists use in folds. Our psoriasis cream overview compares topical options in more depth.

Systemic and Biologic Therapies

When inverse psoriasis is severe, widespread, or not responding to topical treatments, systemic therapy is warranted. Biologic medications targeting IL-17 (secukinumab, ixekizumab), IL-23 (guselkumab, risankizumab), and TNF-alpha (adalimumab) are all effective for inverse psoriasis as part of overall psoriasis management [14]. Some studies suggest that IL-17 inhibitors may be particularly effective for genital psoriasis, with rapid improvement in symptoms and quality of life [3].

Oral options such as apremilast (a PDE4 inhibitor) and methotrexate are also used for moderate to severe psoriasis. Biologics are usually prescribed by a dermatologist, or by a rheumatologist when psoriatic arthritis is present, and they require screening tests before starting. Our guide to psoriasis biologics explains how the drug classes compare.

Phototherapy and other approaches

Narrowband UVB phototherapy works well for widespread plaque psoriasis but reaches skin folds poorly, because the folds are shielded from light, and the genitals are usually covered during treatment. Some integrative and functional medicine clinics also offer approaches such as dietary changes, ozone therapy or red light therapy for psoriasis. The evidence for these in inverse psoriasis specifically is thin, they are generally cash pay, and they work best as additions to dermatology care rather than replacements. Our psoriasis diet article reviews what nutrition research does and does not show.

Lifestyle Management Tips

In addition to medical treatment, these practical steps can help manage inverse psoriasis:

• Keep folds dry: After bathing, thoroughly (but gently) dry all skin folds. Some patients benefit from using a hair dryer on a cool setting.
• Wear breathable fabrics: Cotton and moisture-wicking materials reduce friction and moisture buildup. Avoid tight-fitting synthetic clothing.
• Manage weight: Obesity creates additional skin folds and worsens existing intertriginous disease. Weight loss has been shown to improve psoriasis severity overall [4].
• Use barrier products: Zinc oxide or petroleum-based barriers can reduce friction and protect irritated skin.
• Treat secondary infections promptly: If you notice increased redness, odor, or satellite pustules, a secondary fungal or bacterial infection may have developed and needs specific treatment [7].

Simple product swaps also help. Fragrance free cleansers, unscented deodorant, soft cotton underwear and bras without underwire reduce irritation in the armpits, groin and under the breasts. Laying a thin cotton or moisture-wicking fabric strip in the inframammary fold keeps skin surfaces apart on hot days.

The Emotional Burden of Inverse Psoriasis

Inverse psoriasis carries a particularly heavy psychological burden. Because it frequently affects the genital area, it can significantly impact sexual health, intimate relationships, and self-image. Studies have found that genital psoriasis causes more distress than psoriasis in other locations, with patients reporting embarrassment, avoidance of intimacy, and reduced quality of life [3]. If inverse psoriasis is affecting your emotional wellbeing or relationships, bring this up with your dermatologist. Effective treatment exists, and you do not need to suffer in silence.

When to See a Dermatologist

If you have a persistent rash in your skin folds that has not responded to over-the-counter antifungal creams, it is worth seeing a dermatologist. This is especially true if you already have psoriasis elsewhere on your body, if the rash has sharply defined borders, or if it keeps coming back after antifungal treatment. A dermatologist can examine the rash, perform any necessary testing, and get you on the right treatment plan.

Also mention joint pain, morning stiffness or swollen fingers and toes, since these can signal psoriatic arthritis and may call for a rheumatologist. A primary care physician can start the process, but board certified dermatologists see inverse and genital psoriasis most often.

Finding Psoriasis Care Near You

Most people with inverse psoriasis are diagnosed and treated by a dermatologist, often with insurance covering the visit and standard prescriptions. Some readers also look for integrative or functional medicine practices that work alongside their dermatologist on diet, weight, stress and skin care. You can browse clinics offering psoriasis treatment across the United States in our directory.

Listing order in the directory is not paid ranking. Featured slots are clearly labeled and capped, Verified means a clinic has passed credential checks rather than paid for placement, and Regenerated.com is free for patients. Inclusion in the directory is not an endorsement, so ask any clinic how its approach fits with your dermatologist's plan. Our guide to Featured, Verified and organic listings explains these labels.

Frequently asked questions

What is inverse psoriasis?

Inverse psoriasis is a type of psoriasis that forms in skin folds such as the armpits, groin, genitals, under the breasts and between the buttocks. It appears as smooth, shiny, sharply bordered red or dark patches with little or no scale, because moisture in the folds stops scale from building up. It affects roughly 21 to 30% of people with psoriasis, is not contagious, and is often first mistaken for a fungal infection or intertrigo.

What does inverse psoriasis look like in the armpit?

Inverse psoriasis in the armpit looks like a smooth, glossy, well-defined red patch on lighter skin or a brown to violet patch on darker skin, filling the hollow of the underarm. It usually has no silvery scale and often appears on both sides. Deodorant, shaving and sweat can make it sting or flare. Unlike a fungal rash, it does not have a scaly advancing edge or clear center.

What are the symptoms of psoriasis under the breasts?

Psoriasis under the breasts causes a shiny red or violet band in the fold beneath the breast, with a sharp edge, a moist surface and often a painful crack along the crease. Itching, burning and soreness tend to worsen with heat, sweat and underwire bras. Yeast infection is common in the same fold, so a dermatologist may take a skin scraping to check for candida before choosing a treatment.

Is inverse psoriasis a fungal infection?

Inverse psoriasis is not a fungal infection. It is an immune mediated skin disease, while tinea and candida are infections caused by fungi and yeast. The two look similar and can occur together, because warm, moist folds also favor fungal growth. A KOH preparation or fungal culture checks for infection, and a biopsy can confirm psoriasis. A fold rash that keeps returning after antifungal cream is a reason to see a dermatologist.

What is the best treatment for inverse psoriasis?

Inverse psoriasis is usually treated with gentle, steroid sparing topical medicines because fold skin is thin and absorbs drugs easily. Dermatologists commonly use tacrolimus 0.1% ointment, pimecrolimus cream, short courses of low-potency steroids such as hydrocortisone 1% or desonide 0.05%, calcipotriol, or roflumilast cream 0.3%. Severe or widespread disease may call for biologics that target IL-17, IL-23 or TNF-alpha. The right choice depends on location, severity and other psoriasis.

Can inverse psoriasis affect the genitals?

Inverse psoriasis commonly affects the genitals, and genital involvement occurs in up to 63% of people with psoriasis at some point, according to Ryan and colleagues (2015). It appears as smooth red or dark patches on the vulva, penis, scrotum, pubic area or inner thighs, usually without scale. Genital psoriasis can be treated with mild topical medicines suited to sensitive skin, and biologics are an option when it is severe.

Related Reading

• Psoriasis: Complete Guide
• Psoriasis Treatment Options
• Psoriasis Biologics Guide
• Psoriasis vs Eczema

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