Vol 50, No 7 (2022)

Rationale: Evaluation of the role of the deep Koebner's phenomenon and traumatization seems to be a promising direction in the search of the solution for the delayed diagnosis of psoriatic arthritis (PsA) in patients with psoriasis. We have put forward the question if joint and ligament abnormalities induced by a trauma or persistent physical activity could be an analogue of the skin isomorphic reaction in psoriasis.

Aim: To identify joint and ligament abnormalities in patients with psoriasis caused by mechanical stress and their association with the deep Koebner's phenomenon and PsA.

Materials and methods: This was an open-label, non-randomized, comparative study in parallel groups in 80 in-patients with psoriasis (recruited in the Dermatovenereological clinic № 1, Ufa); the control group included 80 in-patients with PsA. All patients were assessed by a dermatovenereologist, including past history, severity of psoriasis, degree of PsA activity, special questionnaires and the presence of an isomorphic reaction in the skin and periarticular tissues. The joints with maximal physical activity were assessed by X-ray. PsA was diagnosed by a rheumatologist.

Results: The patients from both groups were matched in terms of age, gender, and duration of psoriasis. Pain, joint stiffness and limitation of mobility were present not only in the PsA group, but also in the patients with psoriasis (35%, 27.5% and 26.2% of the patients, respectively). Despite most of the patients in the psoriasis group had no active complaints (65.0% vs. 0% in the control group, p < 0.001), clinical signs of inflammation of the tendons and entheses and relevant history were found in 47.5% (68.7% in the control group, p = 0.007). Hand tendinitis was most prevalent symptom in both groups: 40.0% (32/80) in the psoriasis group and 63.7% (51/80) in the PsA group (p = 0.003). Achilles tendon lesions were found in 17.5% (14/80) and 52.5% (42/80) (p < 0.001) and periarticular edema in 27.5% (22/80) and 63.7% (51/80), respectively (p < 0.001). The combination of these signs with psoriatic plaques in this area was observed in 32.5% (26/80) and 92.5% (74/80) of the patients, respectively (p < 0.001). The comparison of the clinical and X-ray data showed that 38 patients with psoriasis and newly diagnosed PsA had had an increased physical load on the affected joints, as well as signs of a deep isomorphic reaction (tendinitis, periarticular edema, or enthesitis near the involved joints). In both groups, the most common form of PsA was distal one (63.2% [24/38] of the patients with newly diagnosed PsA and 58.7% [47/80] of the patients with previously diagnosed PsA, p = 0.648).

Conclusion: Involvement of the periarticular tissues, as well as early, including preclinical, X-ray abnormalities in the joints of patients with psoriasis can be associated with increased physical activity and the deep Koebner's phenomenon. Therefore, even if patients with psoriasis do not have any clinical manifestations of PsA and no complaints when seen by a dermatovenereologist, it is recommended to perform a detailed collection of past history data with clarification of the type of physical activity and past trauma, as well as to examine both by inspection and palpation the periarticular tissues (tendons and entheses), for the timely use of X-ray examination, consultation of a rheumatologist aimed at diagnosis of psoriatic arthritis.

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.