Ingrown nail

Ingrown nail
Classification and external resources
ICD-10	L60.0
ICD-9	703.0
DiseasesDB	29440
eMedicine	emerg/593 ped/942

Onychocryptosis (also known as an "Ingrown nail," or "Unguis incarnatus"^[1]) is a common form of nail disease. It is an often painful condition in which the nail grows so that it cuts into one or both sides of the nail bed. While ingrown nails can occur in both the nails of the hand and feet, they occur most commonly with the toenails.

An "ingrown" toenail often is not really an "ingrown" toenail at all. The appearance of being ingrown may actually be a result of inflammation of the flesh around the nail. The nail becomes embedded and soft under the flesh that has inflamed around it.

Signs and symptoms

Symptoms of an ingrown nail include pain along the margins of the nail (caused by hypergranulation that occurs around the aforementioned region), worsening of pain when wearing tight footwear, and sensitivity to pressure of any kind, even the weight of bedsheets. Bumping of an affected toe can produce sharp, even excruciating, pain as the tissue is punctured further by the nail. By the very nature of the condition, ingrown nails become easily infected unless special care is taken to treat the condition early on and keep the area clean. Signs of infection include redness and swelling of the area around the nail, drainage of pus, and watery discharge tinged with blood. The main symptom is swelling at the base of the nail on the side the nail is ingrowing (may be both sides).

Causes

The main cause of onychocryptosis or "ingrown nail" is wearing unsuitable footwear, including shoes with inadequate toe-box room and tight stockings that apply top and or side pressures; next is the damp wet atmosphere toes are subjected to all day in enclosed shoes, softening the nail-plate and swelling the epidermis keratin, which eventually increases the convex arch permanently; next is genetics; and last are trauma and disease.

Improper cutting of any nail may cause the nail to cut into the side-fold skin from growth and impact, whether or not the nail is "ingrown" (true onychocryptosis). The nail bends inwards or upwards depending on the angle with which it has been cut. If the tool used for cutting the nails, such as scissors, is in an attitude where the lower blade is closer to the toe than the upper blade then, that will cause the toenail to start growing from its base upwards, and vice versa. The process is visible along the nail as it grows, appearing as a warp that advances towards the end of the nail. The upper corners turn more easily than the center of the nail tip. As people cut their nails by holding the tool always in the same angle, they induce these conditions by accident; as the nail turns closer to the skin, it becomes harder to fit the lower blade in the right attitude under the nail. When cutting a nail, it is not just the correct angle that is important, but also how short it is cut. A shorter cut will bend the nail more, unless the cut is even on both top and bottom of the nail.

Causes may include:

1. Bad nail-care, including cutting the nail too short, rounded off at the tip or peeled off at the edges instead of being cut straight across^[2]
2. Ill-fitting shoes, as those that are too narrow or too short can cause bunching of the toes in the developmental stages of the foot (frequently in those under 21), causing the nail to curl and dig into the skin
3. Trauma to the nail plate or toe, which can occur by stubbing the toenail, dropping things on the toe or going through the end of the shoes (as during sports or other vigorous activity), can cause the flesh to become injured and the nail to grow irregularly and press into the flesh
4. Predisposition, such as abnormally shaped nail beds, nail deformities caused by diseases, or a genetic susceptibility
5. Ingrown toenails may be the result of a bacterial infection, treatable with antibiotics. See Treatments.

A more physiologically sound description is that an "Ingrown Toenail" is actually too much skin around the nail ("Overgrown Toeskin")—the nail is not the problem. Vandenbos and Bowers theorized that pressure necrosis of the soft tissues surrounding the nail due to weight-bearing is the primary cause of ingrowing toenails. They wrote "the term 'ingrown toenail' is unfortunate in that it incriminates the nail as the causative factor and is responsible for the fact that most operative and conservative treatments are directed toward the nail. It is our thesis that persons who develop this condition have an unusually wide area of tissue medial and lateral to the nail and that with weight bearing this tissue tends to bulge up around the nail. When such persons trim the nail in a curved or rounded fashion instead of straight across, further bulging of soft tissue is allowed, and as the nail grows out, pressure necrosis of soft tissue occurs. If our thesis that the fault lies not with the nail but with an excess of soft tissue is correct, treatment by removal of a segment of nail is not rational. It increases the relative amount of soft tissue and predisposes to recurrence and at the same time inept attempts to remove some nail matrix lead to faulty regrowth of the nail. The logical conclusion is that soft tissue should be excised, so that with weight bearing there will be no tissue to bulge up across the nail."^[3].

One study compared patients with ingrown toenails to healthy controls and found no difference in the shape of toenails between patients and controls and suggested that treatment should not be based on the correction of a non-existent nail deformity^[4]. Ingrown toenails are caused by weight-bearing (activities such as walking, etc.) in patients that have too much soft tissue (skin) on the sides of the nail. Weight bearing causes this excessive amount of skin to bulge up along the sides of the nail. The pressure on the skin around the nail results in the tissue being damaged, resulting in swelling, redness and infection.

In the past (and still today) the most common treatments are mainly directed at the nail (Paradigm Paralysis). Treatments often include removal of part or all of the nail. But since the nail is normal and the problem of too much skin around the nail is not treated, this often results in the problem returning or in deformity/mutilation of the nail. Not surprisingly, patient satisfaction reflects this.

Prevention

The most common place for ingrown nails is in the big toe, but ingrowth can occur on any nail. Ingrown nails can be avoided by cutting nails straight across; nails should not be cut along a curve, nor should they be cut too short. The important thing to avoid is cutting the nail shorter than the flesh around it. Footwear which is too small or too narrow, or with too shallow a 'toe box', will exacerbate any underlying problem with a toenail.

It may not be so critical that the nails be cut perfectly 'straight across' as this may imply that they be squared at the corners. Leaving sharp square corners may be uncomfortable and cause snagging on socks. The important thing to keep in mind is that you want to be able to see the corners. You should be able to see the side edge of the nail as it meets the front edge of the nail. This way, you can be sure there is no 'splinter' veering off to the side and growing into your toe. Careful filing of the corner is reasonable. For some people the nail curves down on the sides, in this case it would be difficult to ever see the side edge of the nail plate and this cutting method does not apply. Some nails require cutting of the corners far back to remove the edge that digs into the flesh, this may be done as a partial wedge resection at your podiatrist's office.

Ingrown toe nails can be caused by injury, commonly blunt trauma where the flesh is pressed against the nail causing a small cut that swells. Also, injury to the nail can cause it to grow abnormally, making it wider or thicker than normal or even bulged or crooked. Stubbing the toenail, dropping things on the toe and 'going through the end of your shoes' in sports are common injuries to the digits. Injuries to the toes can be prevented by wearing properly fitting shoes, especially when working or playing.

One myth is that a V should be cut in the end of the ingrown nail; this myth is untrue. The reasoning of the myth is that if one cuts a V in the nail, the edge of the nail will grow together as the nail grows out. This does not happen - the shape of the nail is determined by the growing area at the base of the toe and not by the end of the nail. A notch does no good, and may do harm if it is cut too deeply.^[5]

Treatment

Treatment of ingrown nails ranges from soaking the afflicted area to surgery. The appropriate method is dictated by the severity of the condition. In nearly all cases, drainage of blood or watery discharge should mean a trip to the doctor, usually a podiatrist, a specialist trained explicitly to treat these conditions. Most practitioners agree that trying to outwait the condition is nearly always fruitless, as well as agonizing, but it can be done as long as the condition is not too severe and if the individual has a high pain threshold.

Unfortunately, many consider that dealing with the nail is the correct way to cure the "ingrown" toenail. This is often incorrect. Ingrown toenails are often the result of a bacterial infection. If the infection is dealt with, the toe (and toenail) will heal itself. Soaking the affected toe in an anti-bacterial solution (such as colloidal silver) for 30 minutes at a time over a period of a few days or taking a course of erythromycin can clear up the infection allowing the toe to heal. Prying up the toenail will often make the infection worse and lead to further inflammation. The best way to deal with it is to leave the nail alone (no squeezing, pressing, lifting) and deal exclusively with the infection.

Home care

In mild cases daily soaking of the affected digit in a mixture of warm water and Epsom salts and applying an over-the-counter antiseptic. This might allow the nail to grow out so it may be trimmed properly and the flesh to heal. Note that infection may be somewhat difficult to prevent in cleaning and treating ingrown nails owing to the warm, dark, and damp environment in shoes.

Peroxide is immediately effective to help clean minor infections but iodine is more effective in the long term as it continues to prevent bacterial growth even after it is dry. However, iodine should not be used on deep wounds. In such cases a physician or podiatrist should be consulted. Also, although bandages can help keep out bacteria, one should never apply any of the new types of spray-on bandages to ingrown nails that show any discharge - preventing drainage will likely cause intense swelling and pain. Removal of spray-on bandages can be achieved with common rubbing alcohol.

Some have advocated placing a small piece of cotton under the nail, specifically the affected area or as close to it as possible. In mild or moderate cases this may help the nail to grow back out from underneath the skin. But other foot doctors warn against the practice as many patients report that it increases spread of infection.^[6] This solution is ineffective in advanced cases and usually only works in the early stages.

Some doctors will apply silver nitrate to granulation tissue (overgrowth of irritated tissue at the side of the nail. This may look like reddish cauliflower, bleeds easily). This may [decrease?] the inflammation of the affected tissue at the side of the nail.

Never ever attempt to alleviate the swelling using a needle, doing so can lead to an infection.

If the infection is dealt with, the toe (and toenail) will heal itself. Soaking the affected toe in an anti-bacterial solution (such as colloidal silver or monatomic silver) for 30 minutes at a time over a period of a few days or taking a course of erythromycin can clear up the infection allowing the toe to heal. Experience demonstrates that prying up the toenail will often make the infection worse and lead to further inflammation. The best way to promote healing is to leave the nail alone (no squeezing, pressing, lifting) and deal exclusively with the infection.

Additionally, footwear is a breeding ground for the bacteria that causes the infection. Socks should be changed at minimum daily, and removed at night to allow the toe to be kept cool and dry. Shoes should be kept dry and treated with an anti-bacterial shoe product to keep bacteria growth at a minimum.

In serious cases these home remedies may be ineffective. When the flesh is excessively swollen and infected (purple skin around natural skin tone) these procedures may not work. These more severe cases where the area around the nail becomes infected, or the nail will not grow back properly, must be treated by a professional.

Another way to deal with the ingrown toenail is to get the portion of your toenail which is growing under the skin removed. This must be performed by a podiatrist. The procedure is usually performed after administering a local anesthetic.Once the toe is numb the podiatrist will be able to remove the offending nail border. Once the nail is removed the nail matrix (aka nail root) can either be destroyed via chemical means by using phenol, or surgically by excising the nail matrix. After either procedure the nail will have to be dressed daily with antibiotic cream and band aids. The goal of these procedures is to permenantly remove the nail border that becomes ingrown, and should prevent ingrowns from happening again. Of the two procedures the surgical procedure usually has a better outcome than the chemical one. Several variations of these procedures are outlined below.

Vandenbos Procedure

The Vandenbos procedure was first described by Vandenbos and Bowers in 1959 in the US Armed Forces Medical Journal (Please refer to Reference section for link). They reported on 55 patients and had no recurrences. Subsequently, Dr. Henry Chapeskie performed this procedure on over 560 patients with no recurrences. Unlike other procedures used to treat ingrown toenails, the Vandenbos procedure doesn't touch the nail. In this procedure, the involved toe is first anesthetized with a digital block and a tourniquet applied. An incision is made proximally from the base of the nail about 5 mm (leaving the nail bed intact) then extended toward the side of the toe in an elliptical sweep to end up under the tip of the nail about 3–4 mm in from the edge. It is important that all the skin at the edge of the nail be removed. The excision must be adequate often leaving a soft tissue deficiency measuring 1.5 × 3 cm. A portion of the lateral aspect of the distal phalanx is occasionally exposed without fear of infection. Antibiotics are not necessary as the wound is left open to close by secondary intention. Postoperative management involves soaking of the toe in warm water 3 times/day for 15–20 minutes. The wound is healed by 4–6 weeks. No cases of Osteomyelitis have been reported. When healed, the nail fold skin remains low and tight at the side of the nail. This procedure can be performed on mild to severe cases, and preferably before anyone has attempted a nail resection.

Ingrown toe before Vandenbos procedure	Intraoperative toe during the procedure	Intraoperative toe during the procedure	Healed ingrown toe after Vandenbos procedure
Healed ingrown toe after Vandenbos procedure	Ingrown toe before Vandenbos procedure	Healed ingrown toe after Vandenbos procedure

Band-Aid method

Procedure for double-sided ingrown nail (demonstrating photos after treatment)

Results of procedure for double-sided ingrown nail

This method is non-invasive and reportedly has a high rate of success. The theory is that by physically pulling the side of the nailbed away from the nail, one can decrease pressure while simultaneously improving drainage and drying of the wound. Digit should be clean and unoiled by ordinary soap for best adhesion of band-aid. The pulling is achieved with an ordinary or elastic adhesive bandage. A user of this method sticks one side of the bandage securely to the immediate area of the nailbed, pulling suitably as the bandage is wound around the digit at an angle so that the other end overlaps the first, but does not cover the wound itself. Thus the second side secures the first and keeps it from coming loose under the tension. Loosening while walking can be a problem but there are other ways to fix bandage.

Application of Band-Aid (wound on right side of nail)

1) Pulling

2) Sticking at an angle

3) Securing

Phenolisation

Toothpick segment as home remedy to prevent ingrowing

Following injection of a local anaesthetic at the base of the toenail and perhaps application of a tourniquet, the surgeon will remove (ablate) the edge of the nail growing into the flesh and destroy the matrix area with phenol to permanently and selectively ablate the matrix that is manufacturing the ingrown portion of the nail (i.e., the nail margin).

This is known as a partial matrixectomy, phenolisation, phenol avulsion or partial nail avulsion with matrix phenolisation. Also, any infection is surgically drained. After this procedure, other suggestions on aftercare will be made, such as salt water bathing of the digit in question. The point of the procedure is that the nail does not grow back where the matrix has been cauterized and so the chances of further ingrowths are very low. The nail is slightly (usually one millimetre or so) narrower than prior to the procedure and is barely noticeable one year later. The surgery is advantageous because it can be performed in the doctor's office under local anaesthesia with minimal pain following the intervention. Also, there is no visible scar on the surgery site and a nominal chance of recurrence.

Although the chances of reoccurrence of ingrown nails in an area that has undergone phenolisation are lower than nails who have just had the ingrown nail removed, if the application of the phenol was improperly performed or an insufficient quantity of phenol was applied to the afflicted area; the nail matrix can regenerate from its partial cauterization and grow new nail. This will result in a recurrence of the ingrown nail in approximately 4–6 months as the skin that the original ingrown nail grew under would also recover from the procedure (but the recovery of the skin either side of the nail is standard in this type of procedure) as well as the nail.

Many patients who suffer from a minor recurrence of the ingrown nail often have the procedure performed again, with wiser patients asking the doctor to revise the procedure and try to assure that the procedure is performed correctly. However, some patients who suffer a more severe recurrence see a podiatrist who will perform the procedure again or resort to a more drastic and permanent solution (such as removal of the entire nail or the Vandenbos Procedure, which is described above) if there are multiple recurrences of the ingrown nail.

Wedge resection

A resected wedge from the left side of the left big toe, shown to scale

Partial removal of the nail or an offending piece of nail. More complex than a complete nail avulsion (removal).

Here, the digit is first injected with a common local anesthetic. When the area is numb, the physician will perform an onychotomy in which the nail along the edge that is growing into the skin is cut away (ablated) and the offending piece of nail is pulled out. Any infection is surgically drained. This process is referred to as a "wedge resection" or simple surgical ablation and is non-permanent (i.e., the nail will re-grow from the matrix). The entire procedure may be performed in a physician's office and takes approximately thirty to forty-five minutes depending on the extent of the problem. The patient is allowed to go home immediately and the recovery time is anywhere from a two weeks to two months barring any complications such as infection. As a followup, a physician may prescribe an oral or topical antibiotic or a special soak to be used for approximately a week after the surgery.

Some physicians will not perform a complete nail avulsion (removal) except under the most extreme circumstances. In most cases, these physicians will remove both sides of a toenail (even if one side is not currently ingrown) and coat the nail matrix on both of those sides with a chemical or acid (usually phenol) to prevent re-growth. This leaves the majority of the nail intact, but ensures that the problem of ingrowth will not re-occur.

Disadvantages: If the nail matrix is not coated with the applicable chemical or acid (phenol) and is allowed to re-grow, this method is prone to failure. Also, the underlying condition can still become symptomatic as the nail grows out over the course of up to a year: the nail matrix might be manufacturing a nail that is simply too curved, thick, wide or otherwise irregular to allow for normal growth. Furthermore, the flesh can be injured very easily by concussion, tight socks, quick twisting motions while walking or just the fact the nail is growing wrongly (likely too wide). This hypersensitivity to continued injury can mean chronic ingrowth; the solution is nearly always edge avulsion by the highly successful phenolisation.

Post-surgery toe with removed nail shard

Recurrence: If the nail becomes ingrown again after a wedge resection more invasive surgery is required. This can often include the destruction of the nail bed. This surgery takes longer than the minor wedge resection. During it the toe will be torniqued and incisions will be made from the front of the toe to around 1 cm behind the rear of the visible part of the nail. These incisions are quite deep and will require stitching and will also scar. The nail will then be cut out, much like a wedge resection and the nail bed broken to prevent regrowth. The nail will be significantly narrower after this surgery and may appear visibly deformed but will not become ingrown again. Note: if undertaking this surgery it is advisable to leave at least four days before walking any further than very short distances as even with painkillers this can be exceedingly painful. It is also important if you are required by your employer to stand for extended periods of time that they be made aware you may be unable to work for 1–2 weeks (at most) depending on your speed of recovery.

Nail avulsion

Toe healing process after nail removal.

In case of recurrence in spite of complete removal, and if the patient never feels any pain before inflammation occurs, the condition is more likely to be onychia which is often confused for an ingrown or ingrowing nail (onychocryptosis).

Complete removal of the whole nail is a simple procedure. Anaesthetic is injected and the nail is removed quickly by pulling it outward from the toe. The patient can return to work immediately. The entire procedure can be performed in approximately 20 minutes and is less complex than the wedge resection above. The nail will grow back. However, in most cases it will cause further problems as it can become ingrown very easily as the nail grows outward. It can be easily injured by concussion and in some cases grows back too thick, too wide or deformed. This procedure can thus result in chronic ingrown nails and is therefore considered a generally unsuccessful solution, especially considering the pain involved.

Accordingly, in some cases as determined by a doctor, the nail matrix is coated with a chemical (usually phenol) so none of the nail will ever grow back. This is known as a permanent or full nail avulsion, or full matrixectomy, phenolisation, or full phenol avulsion. As can be seen in the images below, the nail-less toe looks much like a normal toe and fake nails or nail varnish can still be applied to the area.

See also

• Onychauxis
• List of cutaneous conditions

Footnotes

References

• Chapeskie H (2008). "Ingrown toenail or overgrown toe skin?". Canadian Family Physician 54 (11): 1561–1562. PMID 19005128. PMC 2592332. http://www.cfp.ca/cgi/content/full/54/11/1561?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=Chapeskie&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT. 
• Vandenbos KQ, Bowers WP (1959). "Ingrown toenail: a result of weight bearing on soft tissue". US Armed Forces Medical Journal 10 (10): 1168–1173. http://www.ingrowntoenails.ca/images/vanderbos/article.htm. 
• Pearson HJ, Bury RN, Wapples J, Watkin DF (1987). "Ingrowing toenails: is there a nail abnormality? A prospective study". J Bone Joint Surg Br 69 (5): 840–842. PMID 3680356. http://www.jbjs.org.uk/cgi/reprint/69-B/5/840. 
• Aksakal AB, Ozsoy E, Gürer M (2003). "Silicone gel sheeting for the management and prevention of onychocryptosis". Dermatol Surg 29 (3): 261–4. doi:10.1046/j.1524-4725.2003.29061.x. PMID 12614420. http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=1076-0512&date=2003&volume=29&issue=3&spage=261. 
• Boll OF (1945). "Surgical correction of ingrowing toenails". J Natl Assoc Chiroprod. 35: 8–9. 
• Kominsky SJ, Daniels MD (2000). "A modified approach to the phenol and alcohol chemical partial matrixectomy". J Am Podiatr Med Assoc 90 (4): 208–10. PMID 10800276. http://www.japmaonline.org/cgi/pmidlookup?view=long&pmid=10800276. 
• Rounding C, Bloomfield S (2005). "Surgical treatments for ingrowing toenails". Cochrane Database Syst Rev (2): CD001541. doi:10.1002/14651858.CD001541.pub2. PMID 15846620. 
• Boberg JS, Frederiksen MS, Harton FM (2002). "Scientific analysis of phenol nail surgery". J Am Podiatr Med Assoc 92 (10): 575–9. PMID 12438504. http://www.japmaonline.org/cgi/pmidlookup?view=long&pmid=12438504. 

External links

• "Ingrown Toenails" Information regarding ingrown toenails and a detailed description of the Vandenbos procedure including pictures, research articles and a video of the procedure
• "Nail Surgery" Chapter 33 of Textbook of Hallux Valgus and Forefoot Surgery, complete text online in PDF file
• "Complete Nail Surgery Photos Photos and comments showing a full nail removal from beginning to end.
• Ingrown toenail