Inverse psoriasis: the diagnostic value of dermatoscopic assessment and the experience of treatment with a combination topical agent (a clinical series)

Abstract

Background: Inverse psoriasis that is characterized by skinfold rash is seen in 12 to 36% of European patients with psoriasis. Isolated involvement of skinfolds can mimic a number of dermatoses with similar location. The differential diagnosis is increasingly frequently based on non-invasive methods, including dermatoscopy. Taking into account the warm and wet milieu of skinfolds, facilitating secondary infection, topical antibacterials and antiseptics are recommended for treatment, along with topical glucocorticosteroids and vitamin D3 analogues. Materials and methods: We have analyzed the results of assessment and treatment of 15 patients with psoriasis of major skinfolds that were admitted to the in-patient department of dermatology. All patients underwent dermatoscopy at 20 magnification. The patients were treated with desensitizing agents, hepatic protectors, and group B vitamins. Topical treatments applied in the rash areas included a combination topical agent containing mometasone furoate (0.5 mg), gentamicin sulfate (1 mg), econazole nitrate (10 mg), and dexpanthenol (50 mg). The treatment was considered effective if the M-PASI decreased at least by 75%; the results were assessed after 7 and 14 days of treatment. Results: In all cases, dermatoscopy of the vulgar psoriasis lesions showed vermilion or red to rosy background with evenly distributed dotted vessels and white scales diffusely located all over the visualized surface. The skinfold lesions were characterized by rosy or red background with evenly distributed dotted vessels, white scales located either as isolated groups, or at the periphery of the visualized areas; some plaques had local erosions, and in one case, hemorrhages. Morphological assessment of the biopsy samples in all patients with isolated skinfold lesions (n = 5) confirmed the diagnosis of psoriasis. Treatment-induced improvement was seen at day 2 to 3, and at day 14, there was a decrease of M-PASI by 90% in 6 (40%) patients and resolution of the lesions in 9 (60%). There were no treatment-associated adverse events or reactions. Conclusion: Dermatoscopy has proved to be a useful tool for non-invasive diagnostics of inverse psoriasis. At low magnification ( 20), its main sign was an even distribution of dotted vessels throughout the visualized area. In a number of cases, the dermatoscopic symptoms additionally included white scales grouped as isolated foci. The addition of the combination topical agent (mometasone furoate, gentamicin sulfate, econazole nitrate, and dexpanthenol) to the standard systemic therapy facilitated almost full resolution of skinfold psoriatic lesions.