Retronychia is a distinct nail condition where the nail plate grows backward, or proximally, embedding itself into the surrounding skin at the cuticle area (the proximal nail fold). This reverse growth causes chronic inflammation and pain, typically affecting the great toenail. The condition is often caused by repetitive trauma, such as wearing ill-fitting shoes, which disrupts the normal forward growth of the nail.
Identifying the Condition and Conservative Management
Retronychia must be distinguished from a common ingrown toenail (onychocryptosis), where the nail edge pierces the skin at the side (lateral) nail fold. A key symptom of retronychia is chronic inflammation of the proximal nail fold, often accompanied by pain and a yellow discoloration of the nail plate (xanthonychia). In advanced cases, the nail may appear thickened, and multiple generations of new nail plates can stack up, pushing the entire nail up and back.
Initial management focuses on removing the factors that caused the trauma, typically repetitive pressure from tight or narrow footwear. Conservative home treatments aim to reduce acute inflammation and pain, allowing the nail to potentially grow out. Soaking the affected toe in warm water can soothe the inflamed area, while gentle cushioning or taping may alleviate pressure on the proximal nail fold.
For cases identified early, a medical professional may recommend applying high-potency topical corticosteroids to the inflamed proximal nail fold. This treatment suppresses inflammation and swelling, which may be sufficient to release the trapped nail plate and restart normal forward growth. If an infection is present, antibiotics may be necessary, but this only addresses the secondary infection, not the underlying mechanical issue.
Professional Medical and Surgical Treatments
When conservative methods fail, particularly in intermediate or late-stage retronychia, a definitive medical intervention is required. Non-surgical treatment involves intralesional corticosteroid injections, typically using triamcinolone, directly into the inflamed proximal nail fold. This targeted injection is highly effective at reducing the severe local inflammation that prevents the nail from moving forward.
The goal of the corticosteroid injection is to reduce inflammatory pressure on the nail matrix (the root of the nail), enabling the plate to resume its normal growth pattern. Complete recovery has been observed in many patients after one or two injection sessions. However, for chronic, late-stage retronychia characterized by pronounced stacking and persistent inflammation, surgical removal of the nail plate is usually required.
The most effective definitive treatment is a partial or total nail avulsion, which is the surgical removal of the nail plate under local anesthesia. This procedure is considered curative in a high percentage of cases (up to 78.2%) because it removes the physical obstruction embedded in the proximal nail fold. Unlike surgery for ingrown toenails, a chemical matricectomy is typically not required for retronychia. The avulsion simply removes the trapped plate, allowing a new, healthy nail to grow.
Preventing Future Episodes
A long-term strategy must be adopted to prevent recurrence once the acute episode of retronychia has been successfully treated. Since the condition is linked to microtrauma, avoiding repetitive pressure on the toenails is paramount, starting with a thorough evaluation of daily footwear.
Shoes should have an adequately wide toe box that does not compress the toes. Individuals should avoid wearing high heels or tight-fitting dress shoes for extended periods. Activities involving repeated forceful contact, such as certain sports or hiking, should be managed with protective footwear and rest if symptoms arise.
Proper nail care also plays a significant role in prevention. Nails should be trimmed straight across, avoiding cuts that are too short or overly rounded at the corners, which can disrupt the nail’s natural forward movement.