CORRECT DIAGNOSIS:

Inverse Psoriasis

DISCUSSION:

Inverse or flexural psoriasis is characterized by shiny, pink to red, sharply demarcated thin plaques. There is much less scale that in untreated chronic plaque-type psoriasis. Often a central fissure is seen. The most common sites of involvement are the axillae, the inguinal crease, the intergluteal cleft, the inframammary region, and the retroauricular folds. Localized fungal and/or bacterial infections can be a trigger for this condition.

TREATMENT:

Patients with inverse psoriasis develop lesions in the axillae, between the buttocks, on the medial aspects of the thighs, and the umbilicus. These sites are easily treated with mild topical corticosteroids but are more susceptible to corticosteroid side effects such as atrophy and the formation of striae. Consequently, nonsteroidal treatments are often utilized. Calcipotriene can be irritating on intertriginous sites but is nevertheless effective. Some have advocated diluting calcipotriene with petrolatum in equal amounts to minimize irritation. If irritation does not develop, the amount of petrolatum added can be reduced.

According to a 2004 study, Pimecrolimus cream 1% is an effective treatment for inverse psoriasis with a rapid onset of action; it is safe and well-tolerated in both adults and children. Tazarotene can be used on the face but is usually too irritating to use in the axillae or groin. Tars and anthralin are likewise irritating in intertriginous sites.

REFERENCES:

Berger, A. W., Elston, D. M., & James, W. D. (2006). Andrews’ diseases of the skin. Philadelphia, PA: Elsevier.

Bolognia, J. L., Jorizzo, J. L., Rapini, R. P., et al. (2003). Dermatology. Spain: Mosby.

Lebwohl, M., Heymann, W. R., Jones, T. H., & Coulson, I. H. (2005). Treatment of skin disease: Comprehensive therapeutic strategies. Mosby.

Gribetz, C., Ling, M., Lebwohl, M., Pariser, D., Draelos, Z., Gottlieb, A. B., Zaias, N., Chen, D. M., Parneix-Spake, A., Hultsch, T., & Menter, A. (2004). Pimecrolimus cream 1% in the treatment of intertriginous psoriasis: A double-blind, randomized study. Journal of the American Academy of Dermatology, 51(5), 820-826. https://doi.org/10.1016/j.jaad.2004.07.013

Steele, J. A., Choi, C., & Kwong, P. C. (2005). Topical tacrolimus in the treatment of inverse psoriasis in children. Journal of the American Academy of Dermatology, 53(4), 690-693. https://doi.org/10.1016/j.jaad.2005.04.032