What causes ingrown toenails?Ingrown toenail, or onychocryptosis, is a common painful disease, usually affecting the big toenail.
Anatomical factors contributing to onychocryptosis include overgrown skin fold around the ungual plate or malformed toenails. Behavioral factors which cause onychocryptosis include poor foot hygiene, improper trimming, tearing toenails off, hyperhidrosis (excessive sweating), repetitive trauma such as running or kicking, or inadvertent trauma such as stubbing the toe.
Factors predisposing lower extremity edema such as obesity, hypothyroidism, cardiac, and renal disorders can also increase the likelihood a person developing onychocryptosis. In older persons, spicule formation and thickening of ungual plate are the causes of ingrown, painful, and infected onychocryptosis.
Poor foot hygieneOur feet are the most abused and neglected part of our body. Tired, sore and neglected feet can develop several problems. Cleaning the feet every evening before going to bed and keeping them dry will keep nearly half of the foot health problems out. Dusty, dirty and moist toenails can contract fungal infections and cause onychocryptosis.
Improper trimmingImproper trimming of toenails may cause onychocryptosis. Toenails should be trimmed straight across. Trimming too close or rounding off the ungual plate edges will result in bulging of soft tissue around it leading to soft tissue injury. Cutting back the lateral margins in a curved manner should be avoided. The toenail edges should extend past the tissue of the lateral skin fold.
HyperhidrosisIn adolescence, feet perspire more often which causes the ungual plate to become soft and prone to splitting. Further, participation in sports or physical activities result in the production of ungual plate spicules. The excessive sweating also causes maceration of the skin of the toenail folds. Such condition makes it easier for the ungual plate or spicules to pierce the surrounding skin.
|infected ingrown toenail caused by ill-fitting shoes|
Overgrown skin foldsOne school of thought is that the toenail is not the real culprit, and that the excess skin surrounding the ungual plate is the real problem. Some individuals have unusually wide area of tissue medial and lateral to the toenail. With weight bearing, this tissue tends to bulge up around the ungual plate, leading to pressure necrosis, and cause the ungual plate to pierce into the soft tissue. The Vandenbos procedure targets removing these excess skin fold around the toenail.
Ill-fitting footwearTight-fitting shoes, narrow toed or pointed shoes or high heeled shoes place constant pressure on the median skinfold and also on lateral skin fold by pushing the big toe against the second toe. Such pressure can cause the toenail plate to cut into the surrounding tissues. Proper footwear with a wide toe area is to be prefered. Tight socks also can create similar problems. If shoes are too loose, toes may constantly hit against the shoe and again increase the chances of developing ingrown ungual plate.
Toenail deformitiesUngual plate apparatus may have several congenital abnormalities. Secondary deformities may arise due to trauma or anatomical conditions. These abnormalities can initiate onychocryptosis. Excessively curved toenail is more curved from side to side rather than being flat. Such a toenail can become ingrown into the adjacent skin fold. Increased or reduced ungual plate thickness, medial rotation of the hallux and related structural abnormalities, deformed shape of the ungual plate, thickened skin folds around the plate can become contributing factors for onychocryptosis.
Congenital factorsCongenital onychocryptosis may be caused by intrauterine disorders or hereditary factors. A newborn may have excessive growth of skin folds surrounding the toenail, congenital hypertrophic lip of hallux, distal embedding with normally directed ungual plate, distal lateral embedding, congenital malalignment of the big toenail or overcurvature of the ungual plate. All these conditions may induce and cause ingrown toenails.
Ingrown toenail in old ageToenails undergo several physiological changes and histological modifications in geriatric populations. These changes are caused by the impairment in circulation, susceptibility to infections, skin disorders, reduced mobility, foot deformities and systemic diseases. They may not be able to take adequate care of legs and feet. The toenails get thickened, hardened and brittle. Poor eyesight, trembling and inability to bend and reach their feet leads to improper trimming of toenails. They tend to stub their toes quite often due to gait problems. These conditions make them prone to have ingrown ungual plate.
Genetic predispositionCambiaghi S et al. in their report titled 'Congenital hypertrophy of the lateral nail folds of the hallux in twins,' published in British Journal of Dermatology (1997) described a case of onychocryptosis in twins. The report suggested the possibility of genetic predisposition to onychocryptosis in some cases.
Other common causes
- Onychocryptosis and paronychia have been reported secondary to use of medications, such as indinavir, retinoids, docetaxel and cyclosporin.
- Subungual neoplasms may result in chronic ingrown conditions by compression on to hard surface of ungual plate.
- Stubbing of toes or repeated injuries to toes may lead to ingrown ungual plate.
- As said earlier systemic diseases such as hypothyroidism, cardiac and renal disorders with predisposition to lower extremity edema can cause ingrown conditions.
- Fungal infections of the toenail cause the ungual plate to become brittle and break into spicules. The spicules may pierce the surrounding skin fold and grow into it.
- Picking or tearing at the corners of the toenails can also cause an ingrown condition.
- Improper posture which transfers much of the body weight on to the toes can influence chances of developing ingrown toenails.
Ingrown toenail treatmentMild, initial stages of onychocryptosis can be treated with conservative approaches, such as soaking the foot in warm, soapy water, placing cotton wisps or dental floss under the ingrown ungual plate edge, using gutter splint or applying topical antibacterial preparations. For highly infected or recurrent ingrown toenail, surgical correction is the treatment of choice.
References on ingrown toenail:|
1.Heidelbaugh JJ, Lee H. Management of the ingrown toenail. Am Fam Physician. 2009 Feb 15;79(4):303-8.
2.Reyzelman AM, Trombello KA, Vayser DJ, Armstrong DG, Harkless LB. Are antibiotics necessary in the treatment of locally infected ingrown toenails? Arch Fam Med. 2000;9(9):930–932.
3.DeLauro NM, DeLauro TM. Onychocryptosis. Clin Podiatr Med Surg. 2004;21(4):617–630.
4.Khunger N, Kandhari R. Ingrown toenails. Indian J Dermatol Venereol Leprol. 2012 May-Jun;78(3):279-89.
5.Chapeskie H. Ingrown toenail or overgrown toe skin? Alternative treatment for onychocryptosis. Can Fam Physician 2008;54:1561-2.