A novel treatment for retronychia: case series

Retronychia in children: A case series

BACKGROUND

Retronychia is characterized by proximal ingrowing of the nail plate into the proximal nail fold. It is always associated with the presence of two or more overlapping nail plates under the proximal nail fold, clinical signs of chronic proximal paronychia refractory to antimicrobial treatment, and a yellowish nail that does not grow. It mainly affects young female adults, with less than 30 pediatric cases described in the literature so far.

METHODS

Retrospective and observational study of patients between 0 and 18 years with a clinical and/or ultrasound diagnosis of retronychia attending a pediatric dermatology service between December 2020 and January 2022.

RESULTS

We identified 9 patients with retronychia, 7 girls and 2 boys. In all cases, the hallux nails were affected with 5 unilateral and 4 bilateral cases. On physical examination we observed the following signs: thickened and opaque nail plate (one patient), yellowish nail plate (7 patients), double nail plate (6 patients), and erythema with edema, pain, and suppuration of the proximal nail fold (7 patients). Ultrasound was performed in 7 patients and specific findings of retronychia were found in 5 of them. All patients received topical treatment and were referred for the appropriate surgical treatment. To date, only one patient underwent nail avulsion, which was followed by complete recovery.

CONCLUSIONS

Retronychia is underdiagnosed, particularly in the pediatric population. We present a series of 9 cases of retronychia in children, with clinical and ultrasonographic findings consistent with those of adults. We emphasize the importance of recognizing this entity, which will allow early and adequate treatment.

Optimal diagnosis and management of common nail disorders

Nail conditions are not only aesthetic concerns, and nail changes may be a clue to an underlying systemic diseases or infection. Without timely treatment, nail diseases can continue to worsen and significantly impair performance of daily activities and reduce quality of life. Examination of the nails is essential at every medical visit, and may uncover important findings. Brittle nail syndrome, onychomycosis, paronychia, nail psoriasis, longitudinal melanonychia, Beau's lines, onychomadesis and retronychia are common nail disorders seen in clinical practice. These conditions stem from infectious, inflammatory, neoplastic and traumatic aetiologies. Though each nail condition presents with its own distinct characteristics, the clinical findings may overlap between different conditions, resulting in misdiagnosis and treatment delays. Patients can present with nail plate changes (e.g. hyperkeratosis, onycholysis, pitting), discolouration, pain and inflammation. The diagnostic work-up of nail disease should include a detailed history and clinical examination of all 20 nail units. Dermoscopy, diagnostic imaging and histopathologic and mycological analyses may be necessary for diagnosis. Nail findings concerning for malignancy should be promptly referred to a dermatologist for evaluation and biopsy. Nail disease management requires a targeted treatment approach. Treatments include topical and/or systemic medications, discontinuation of offending drugs or surgical intervention, depending on the condition. Patient education on proper nail care and techniques to minimize further damage to the affected nails is also important. This article serves to enhance familiarity of the most common nail disorders seen in clinical practice. It will highlight the key clinical manifestations, systematic approaches to diagnosis and treatment options for each nail condition to improve diagnosis and management of nail diseases, as well as patient outcomes.Key messagesNail disease is not only a cosmetic issue, as nail changes can indicate the presence of a serious underlying systemic disease, infection or malignancy.Nail pain and changes associated with NP are physically and emotionally distressing and may contribute to functional impairment and diminished quality of life.LM is a hallmark sign of subungual melanoma and this finding warrants further investigation to rule out malignancy.

Treatment of retronychia: A systematic review and suggested treatment algorithm

Retronychia is an inflammatory disorder typical of the great toes characterized by arrested nail growth, ingrowth of the nail plate into the proximal nail fold and paronychia. There is no standardized treatment for retronychia, and its management should be weighed based on the severity stage, treatment modality, and clinical outcome. In this paper, a systematic review of the literature was performed to assess all published data regarding the treatment of retronychia. A total of 231 patients from 24 studies were included in the analysis. Conservative management was adopted in mild-intermediate forms, consisting of medical (topical or intralesional high-potency corticosteroids) and podiatric treatment (taping, clipping back the onycholytic plate, orthosis), leading to a global cure rate of 41.2%, with no reported side effects. Non-conservative management, that is, chemical or surgical avulsion of the nail plate, proved resolutive in 71.2% of cases. Surgical avulsion of the nail plate produced the highest cure rate (78.2%), but was burdened by 9.6% of long-term sequelae, mainly nail dystrophies. A decision-making algorithm was designed to give clinicians treatment indications based on the severity stage of retronychia, treatment invasiveness, and possible clinical outcomes.

Retronychia: A Paradigm Shift?

Retronychia is an increasingly known cause of paronychia. It was classically regarded as an indication for total nail plate avulsion, but recent case series have questioned the real need for this approach. In order to establish a proper recommendation for patients presenting with retronychia, we retrospectively reviewed all articles with retronychia case reports. Total nail plate avulsion is still the most efficient treatment option. Topical steroids and other noninvasive approaches can be useful in some early, mild cases, but further prospective studies are needed in order to access their efficacy.