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Whether you’ve been diagnosed with psoriasis or suspect you may be dealing with this skin disease, those red, scaly, rough patches can be uncomfortable and a nuisance.
There are different types of psoriasis, and understanding which one you may be dealing with is important for diagnosis and treatment. One form of psoriasis is inverse psoriasis.
What is inverse psoriasis?
Inverse psoriasis—also known as flexural psoriasis—is a subtype of psoriasis that creates red, inflamed lesions in the body’s skin folds. On skin of color, it often looks purple-ish, brown, or darker than the surrounding skin. The lesions are prevalent in areas like the armpits, back of the knees, elbow creases, and in the folds of the skin of the genital area (Micali, 2019).
It’s thought that 21% to 30% of people who currently have psoriasis develop inverse psoriasis (Merola, 2016). Other research states that the range of prevalence is between 3% to 36%, with infants skewing higher, commonly dealing with it in the diaper area or folds of the legs (Micali, 2019).
Stress rash: causes and treatments
Symptoms of inverse psoriasis
The symptoms of inverse psoriasis are like other symptoms of psoriasis, with the location of inflammation as one of the major differentiating factors. Those who may have inverse psoriasis will experience (Micali, 2019):
- Red patches, or splotchy, raised patches of skin
- Inflammation of the surrounding body folds
- Lesions—an area of the body that becomes abnormal, expanding or causing skin breakage
- Possible bacterial growth or fungal infections within the skin folds affected
Causes of inverse psoriasis
Inverse psoriasis is caused by several factors, which are mainly genetic as well as environmental. Approximately one-third of those who deal with psoriasis have a family history of it, including inverse psoriasis (Weigle, 2013). Besides genetics, many of the same environmental causes of psoriasis may also cause inverse psoriasis. These include (Kamiya, 2019):
- Taking specific medications
- Drugs and alcohol
- High or unhealthy body mass index (BMI)
- Underlying infections
- Certain endocrine disorders like diabetes
The most significant risk factor is having a first-degree family member with the condition. However, aside from genetic predispositions, certain things may exacerbate it, including (Kamiya, 2019):
- Extreme mental stress
Inverse psoriasis may be difficult to correctly pinpoint without a diagnosis of psoriasis in its other generalized forms. Should an individual have a psoriasis diagnosis, however, much of an inverse psoriasis diagnosis relies on where the psoriasis is occurring on the body (Micali, 2019).
If it presents in places like the folds of the skin, a healthcare provider will first want to rule out a bacterial infection and external causes—like the friction of the skin rubbing together or against clothing that may cause irritation (Micali, 2019).
This is all done in tandem with a healthcare provider taking a detailed personal and family health history. In certain rare cases, they may perform a skin biopsy in instances with no other complications aside from the psoriasis itself (Micali, 2019).
Although many of the same types of treatment options that work for psoriasis are applicable for inverse psoriasis, a healthcare provider may take certain precautions or considerations when treating it because of its location on particularly sensitive areas of the skin (Hong, 2021).
There are several topical medications and systemic therapies. Topical treatments include topical corticosteroids applied on the affected areas, calcineurin inhibitors, phosphodiesterase-4 inhibitors, vitamin D, anti-fungal creams, and certain coal tar preparations (Hong, 2021).
As for systemic therapies, oral medication and biologics such as IL-17 inhibitors can be used and have shown efficacy in treating inverse psoriasis in genital areas (Hong, 2021).
Since inverse psoriasis has such a strong genetic component, it’s challenging to prevent it entirely. But adopting healthy lifestyle habits such as maintaining a healthy weight, avoiding smoking and drinking, and managing stress can lessen the frequency of flare-ups (Weigle, 2013).
When to see a doctor
If your inverse psoriasis is causing you pain, embarrassment, lack of self-esteem, or hindering sexual function or your social life, it’s important to see your healthcare provider or make a dermatology appointment.
Treatment is essential to physically improve symptoms, improve quality of life, and lessen the mental burden psoriasis can cause (Cohen, 2016). A dermatologist or primary care physician can help provide this relief.
- Cohen, J., Halim, K., et al. (2016). Shedding Light on the “Hidden Psoriasis”: A Pilot Study of the Psoriasis Burden of Disease (IPBOD) Questionnaire. Journal of Drugs in Dermatology, 15(8), 1011-1016. Retrieved from https://pubmed.ncbi.nlm.nih.gov/27538004/
- Hong, J. J., Mosca, M. L., Hadeler, E. K., Brownstone, N. D., Bhutani, T., & Liao, W. J. (2021). Genital and Inverse/Intertriginous Psoriasis: An Updated Review of Therapies and Recommendations for Practical Management. Dermatology and Therapy, 11(3), 833–844. doi: 10.1007/s13555-021-00536-6. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8163914/
- Kamiya, K.,, M., Sugai, J., Komine, M., & Ohtsuki, M. (2019). Risk Factors for the Development of Psoriasis. International Journal of Molecular Sciences, 20(18), 4347. doi: 10.3390/ijms20184347. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6769762/
- 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. Clinical and Experimental Dermatology, 41(5), 486–489. doi: 10.1111/ced.12805. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4915990/
- Micali, G., Verzì, A. E., Giuffrida, G., Panebianco, E., Musumeci, M. L., & Lacarrubba, F. (2019). Inverse Psoriasis: From Diagnosis to Current Treatment Options. Clinical, Cosmetic, and Investigational Dermatology, 12, 953–959. doi: 10.2147/CCID.S189000. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6997231/
- Weigle, N., & McBane, S. (2013). Psoriasis. American Family Physician, 87(9), 626-633. Retrieved from https://www.aafp.org/pubs/afp/issues/2013/0501/p626.html
Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.