Toenail fungus, or onychomycosis, is a medical condition in which the toenail is infected with fungal spores or fungal organisms. In Singapore, the condition affects slightly more males than females. In a local study, the age of patients ranged from 8-82 years with a median of 45 years.

Toenail fungus symptoms

The symptoms associated with toenail fungus are thickened, deformed and discoloured (yellow, green or white) toenails. At times toenails can also appear brittle with some amount of debris underneath the nail.

Causes of toenail fungus

Fungal toenails are caused by fungal organisms such as dermatophytes and yeast (Candida) colonising and eventually infecting the nail plate (nail bed). In a dark, warm and moist environment, the fungus thrives and feeds on the nail plate. This eventually causes changes to the nail plate. Fungal spores are tiny and invisible to the naked eye. They can be found in our ordinary, surrounding environment.

Toenail fungus risk factors

Risk factors that increase the susceptibility for fungal toenail infections include:

  • Low immune system associated with chronic diseases such as diabetes and immune disorders.
  • Poor foot hygiene.
  • Ageing, as nail growth generally slows down over time.
  • Reduced blood flow to the toes (poor blood circulation).
  • Wearing closed shoes for long hours. This creates an optimal environment for fungal growth, especially in the tropical Singaporean climate.

Complications of toenail fungus

The common complications of toenail fungus are:

  • Brittle, ugly-looking toenails
  • Secondary fungal and/or bacterial infection, such as cellulitis (patches of skin turning red, painful, swollen and hot)
  • Painful toenails
  • Permanent damage to the affected toenails
  • Ingrown toenails

Tests and diagnosis to confirm ​toenail fungus

To confirm the presence and type of nail fungus, nail clippings are sent to the pathology lab for culture and histology tests.

Visual appearance, such as distortion and discolouration of the toenail, can also be a good indicator, especially in moderate to advanced stages.

In a clinical setting, an ultraviolet light (Wood’s lamp) can also be used in a dark room to reveal fungal infection of the nail plate.

Learn more about the treatment for toenail fungus and how to prevent it.

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