inverse psoriasis inverse psoriasis inverse psoriasis or flexural psoriasis is a form of psoriasis that selectively, and often exclusively, involves the folds, recesses, and flexor surfaces such as the ears, axillae, groin folds, inframammary folds, navel, intergluteal cleft, penis, and lips.: 193 inverse psoriasisspecialtydermatology diagnosis differential diagnosis skin conditions which can present with similar signs and symptoms include seborrheic dermatitis, intertrigo, and tinea versicolor.