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Inverse psoriasis in Adult
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Inverse psoriasis in Adult

Contributors: Jeffrey M. Cohen MD, Susan Burgin MD
Other Resources UpToDate PubMed


Inverse psoriasis, also known as intertriginous or flexural psoriasis, is a form of psoriasis that presents in skin folds such as the inframammary areas, the axillae, and the inguinal folds. The plaques of inverse psoriasis are morphologically similar to those of classic plaque psoriasis in that they are erythematous and sharply demarcated; however, inverse psoriasis lacks the thick silver scale, and instead has a surface that is smooth, moist, and sometimes macerated. Mechanical friction of opposing skin surfaces within flexural zones is thought to result in koebnerization (isomorphic response), which perpetuates the condition.

Inverse psoriasis affects up to 30% of patients who have plaque psoriasis, and it most commonly presents in the inguinal folds. The external genitalia is involved in up to 80% of individuals with inverse psoriasis.

Lesions may be pruritic, irritated, or painful. Inverse psoriasis is also associated with a decreased quality of life and may adversely impact intimate relationships.


L40.8 – Other psoriasis

238600001 – Flexural psoriasis

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • Tinea corporis – Will have positive potassium hydroxide (KOH) examination.
  • Intertrigo with secondary bacterial infection.
  • Candidiasis – "Beefy" red erythema or satellite pustules prompt concern for candidiasis.
  • Erythrasma – With "coral red" fluorescence by Wood's lamp examination.
  • Seborrheic dermatitis – Can be difficult to exclude, even histologically.
  • Hailey-Hailey disease (benign familial pemphigus) – An inherited acantholytic disorder with characteristic histologic findings. Clinically, plaques are more moist and fissuring is often more apparent.
  • Darier disease (keratosis follicularis) – An inherited acantholytic disorder with characteristic histologic findings; unusual in the genital area.
  • Subcorneal pustular dermatosis (Sneddon-Wilkinson disease) – Annular plaques with pustules along the border and often clear center.
  • Impetigo herpetiformis – Occurs during pregnancy; pustules occur at the margins of the lesions.
  • Genital lichen sclerosus – Atrophic, blue-white plaques.

Best Tests

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Management Pearls

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Last Reviewed:07/25/2018
Last Updated:09/03/2018
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Inverse psoriasis in Adult
Inverse psoriasis : Erythema, Flexural distribution, Intertriginous distribution, Scaly plaque, Pruritus
Clinical image of Inverse psoriasis
Well-demarcated, salmon-pink papules with scant scale and a similar plaque in the axilla.
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