Resumen

Objectives: To evaluate the efficacy of using intralesional corticosteroid applied to the nail matrix in conjunction with total avulsion to decrease post-treatment onychodystrophy or recurrences of retronychia cases compared to standard surgical treatment. Introduction: Retronychia occurs due to the ingrowth of the nail plate into the proximal nail fold. It is often suspected in cases of persistent paronychia, especially after trauma. This disorder is likely underdiagnosed due to low awareness among dermatologists and incomplete clinical presentations. Ultrasound can be a valuable tool in cases of diagnostic uncertainty. Nail plate avulsion remains the preferred diagnostic and curative method in chronic stages but post-surgical complications have been observed. Currently, there are no alternative treatments with better results. Materials / method: A cohort study was conducted, analyzing the database of patients diagnosed with retronychia at a reference hospital in Santiago, Chile. Group 1 (2021-2023) received total nail avulsion treatment for retronychia, and group 2 (2024) received avulsion plus corticosteroid injection into the nail matrix. Subsequent controls evaluated the presence of post-surgical onychodystrophy or recurrence between the two groups. Post-surgical outcomes, including onychodystrophy and recurrence, were compared between the two groups. Clinical, demographic, and complication data were analysed. Results: Group 1 included 37 patients, and Group 2 16 patients. Average age in Group 1 was 29.8 years, and in Group 2 29.4 years. 25% of cases with previous nail trauma in Group 1 and 37.5% in Group 2. Ultrasound was used in 43.2% of Group 1 and 31.2% of Group 2. The nails affected were exclusively first toe in 86.4% of Group 1 and 87.5% of Group 2. Follow-up for Group 1 was effective in 94.5% of cases, with an average follow-up of 14.9 months. In Group 2, it was effective in 93.7%, with average follow-up of 13.3 months. Percentage of post-surgery nail alteration was 45.9% in Group 1 and 25% in group 2 Conclusion: This pilot study in Chile suggests that a combined treatment of nail avulsion and intralesional corticosteroid may be more effective in reducing post-surgical onychodystrophy and recurrences in patients with retronychia, compared to avulsion alone. Preliminary results are promising, indicating that the corticosteroid may help control underlying inflammation and improve long-term outcomes. However, larger, long-term studies are needed to confirm these findings and establish the long-term efficacy of this approach.