Retronychia is a type of ingrown nail where the toenail ingrows at the cuticle (or more specifically, the proximal nail fold) rather than at the sides of the nail plate. The nail plate grows backward into the nail bed, and can be very painful.
It is characterised by repeated flares of infection (paronychia; this can be low-grade and not require antibiotics) and inflammation (swelling) at the cuticle, and is typically caused by repeated trauma e.g. walking downhill for a long time, or shear/friction from running in ill-fitting footwear.
Retronychia tends to follow a pattern of nail growth, followed by a flare (pain, redness, swelling), then the nail may drop off - and the cycle repeats.
Sometimes it will rectify itself if carefully managed. In some cases, minor surgery is required to remove the nail plate(s); the stop/start nature of the process can lead to multiple nails growing on top of one another. Surgery will 'reset' the nail growth, and a new normal nail should form. This can be performed in clinic by a podiatrist, and there is minimal downtime required.
Causes of Retronychia
Retronychia usually occurs when the growth of the nail is interrupted, leading to the new nail growing beneath the existing nail rather than pushing it forward. Factors that can contribute to this condition include: -
Trauma
Injuries to the nail or nail bed, such as stubbing a toe, can disrupt normal nail growth and lead to retronychia.
Repeated Pressure
Activities that cause shunting of the ends of the toenails, like running or wearing tight shoes.
Nail Disorders Some underlying nail disorders or abnormalities in nail growth can predispose a person to retronychia.
Delayed Nail Growth
Conditions that slow down nail growth (poor circulation, chronic illness, chemotherapy) can also contribute, as the nail growth is disturbed. Anecdotally, a stop/start cycle of growth seems causative in retronychia.
Symptoms of Retronychia
The main symptoms of retronychia include:
- Pain
- Swelling
- Inflammation
- Thickened Nail Plate
- Discoloration of nail plate
- Separation of nail plate from nail bed
Diagnosis
Diagnosis is made on clinical grounds, typically by an experienced podiatrist. Less experienced clinicians may diagnose this condition as an ingrowing toenail.
Conservative Treatments - Antibiotics: If there is an infection, antibiotics may be prescribed to treat it.
- Footwear Modifications: Wearing shoes that reduce pressure on the toes can help prevent further damage and promote proper nail growth.
- Topical Treatments: In some cases, topical treatments, such as hydrocortisone 1% cream, may be helpful to reduce inflammation.
Surgical Treatment It is not uncommon for the nail to require removal. Unlike typical ingrown toenail surgery, no phenol (chemical cautery) is required – so the healing time is significantly reduced and the relief from symptoms is instantaneous.
- Partial or Complete Nail Avulsion: This is the most common treatment, where part or all of the affected nail is surgically removed. This allows the nail bed to heal and the nail to regrow properly.
Prognosis
With proper treatment, retronychia typically resolves without long-term complications, although the regrowth of the nail will take several months. If left untreated, it can lead to chronic pain, persistent inflammation, and recurring infections.
Conclusion
Retronychia is a painful nail condition where the nail grows backward into the nail bed. It requires medical intervention by a suitably qualified podiatrist to prevent complications and to restore normal nail growth.
If you suspect you have retronychia, it's important to consult with a podiatrist for proper diagnosis and treatment.
For more information or to arrange an assessment, please get in touch!