Retronychia is a specific, often painful nail disorder where the nail plate grows backward, embedding itself into the proximal nail fold (the tissue at the very base of the nail). This condition is frequently triggered by acute or repetitive trauma, such as wearing tight footwear or engaging in activities that cause microtrauma to the toes. The backward growth causes chronic inflammation, and because the new nail cannot grow forward, it pushes the old nail up, leading to a characteristic layering of multiple nail plates. Because the symptoms can closely resemble a common infection, retronychia is often missed or misdiagnosed, complicating effective treatment.
Identifying Retronychia for Correct Diagnosis
Retronychia can be difficult to diagnose because its initial presentation is often confused with chronic paronychia, a common bacterial or fungal infection around the nail. A distinguishing sign of retronychia is the absence of purulent discharge (pus), which is typically present in a simple bacterial infection. Instead, the condition involves inflammation and swelling concentrated at the proximal nail fold, not the lateral edges of the nail. The affected nail may also show a yellowish discoloration (xanthonychia) and a noticeable thickening of the nail plate.
The most characteristic physical finding is the stacking of nail layers, where new nail plates grow underneath the old, impacted plates, leading to a thickened, layered appearance. In chronic cases, the cuticle may be absent. To confirm the diagnosis and rule out other causes, such as subungual tumors, advanced imaging like high-frequency ultrasound is sometimes necessary. Ultrasound can clearly reveal the presence of multiple overlapping nail plates and the decreased distance between the nail matrix and the bone, which are definitive signs of the condition.
Initial Conservative Treatment Approaches
For cases that are caught early, conservative, non-surgical approaches are the first line of treatment, aiming to reduce inflammation and allow the nail to resume normal growth. High-potency topical corticosteroids or anti-inflammatory medications, sometimes administered through intralesional injection directly into the proximal nail fold, are used to decrease the swelling and irritation. The goal of this localized therapy is to alleviate the pressure on the nail matrix and encourage the trapped nail plate to dislodge.
Physical manipulation techniques can also be beneficial in the early stages, including gentle massage of the toe in a distal-plantar direction or the use of adhesive taping to pull the soft tissue away from the nail. Clipping back the onycholytic (separated) portion of the nail plate can relieve some pressure. While these non-invasive methods carry a lower risk of side effects, they are only successful in about 41% of cases, and they are generally insufficient for advanced or recurrent retronychia.
Surgical Options for Permanent Resolution
When conservative treatments fail or the condition is advanced, surgical intervention is typically required for definitive resolution, with a success rate around 78%. The standard procedure is Proximal Nail Plate Avulsion, which involves surgically removing the embedded, thickened portion of the nail plate under local anesthesia. The surgeon carefully detaches the impacted nail from the proximal nail fold, revealing the multiple stacked layers that confirm the diagnosis.
This procedure is focused on removing the mechanical obstruction without damaging the nail matrix, which is responsible for growing the new nail. A tourniquet is applied to the toe to create a bloodless field, and the nail plate is lifted and removed from the proximal end. In rare, severe, or highly recurrent cases where the matrix is significantly damaged, a more extensive procedure like partial or total matricectomy might be considered to prevent future growth of the problematic nail. The immediate goal is to completely clear the proximal nail fold to allow for the healthy, forward regrowth of a single nail plate.
Post-Treatment Care and Follow-Up
Following surgical avulsion, meticulous post-treatment care is necessary to ensure optimal healing and minimize the risk of recurrence. The immediate recovery involves proper wound care, which includes keeping the exposed nail bed clean and dry and applying non-adherent dressings as instructed by the surgeon. Pain medication is typically prescribed to manage discomfort in the days immediately following the procedure. Monitoring the site for signs of infection, such as increased redness, swelling, or persistent pain, is an important part of the initial follow-up.
Long-term management focuses on prevention, as even after successful treatment, the condition can recur due to continued trauma. Patients should wear properly fitting, comfortable shoes that do not exert pressure on the toes, particularly the great toenails, which are most commonly affected. Avoiding activities that cause repetitive microtrauma is also recommended, along with ensuring the regrowing nail is trimmed straight across and not too short. Follow-up appointments are scheduled to monitor the healthy regrowth of the new nail, which can take up to a year.