What causes cloudy fingernails?

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From the Guidelines

Cloudy fingernails are most commonly caused by fungal infections, such as onychomycosis, which can be treated with antifungal medications like terbinafine or itraconazole 1.

Causes of Cloudy Fingernails

  • Fungal infections (onychomycosis): caused by fungi invading the nail bed, leading to discoloration, thickening, and a cloudy appearance 1
  • Psoriasis: creates pitting and discoloration on the nail plate 1
  • Trauma to the nail: damages the nail bed, leading to abnormal nail growth and appearance 1
  • Allergic reactions to nail products: can cause nail discoloration and damage 1
  • Systemic conditions: such as thyroid disorders or nutritional deficiencies, can affect nail health and appearance 1
  • Poor circulation: can contribute to cloudy nails by reducing blood flow to the nail bed 1

Treatment and Prevention

  • Antifungal medications: such as terbinafine (250mg daily for 6-12 weeks) or itraconazole (200mg twice daily for one week per month, for 2-3 months) can be effective in treating fungal infections 1
  • Keeping nails dry: and avoiding artificial nails can help prevent fungal infections 1
  • Wearing breathable footwear: can help reduce moisture and prevent fungal growth 1
  • Applying antifungal powders: or sprays to shoes and feet can help eliminate fungal elements and prevent reinfection 1

Importance of Proper Diagnosis

If you notice persistent nail changes, it's essential to consult a healthcare provider for proper diagnosis, as the appropriate treatment depends on the underlying cause 1.

From the Research

Causes of Cloudy Fingernails

  • Fungal infections, particularly those caused by dermatophytes, yeasts, and molds, can lead to cloudy fingernails 2, 3, 4.
  • Bacterial infections, such as those caused by Pseudomonas aeruginosa, can also cause cloudy or discolored fingernails 2.
  • Onychomycosis, a fungal infection of the nail, can cause cloudy, thickened, or brittle nails 4, 5, 6.
  • Other factors, such as impaired blood circulation, peripheral neuropathy, diabetes mellitus, and limited immune defects, can predispose the nail to fungal infection 4.

Types of Fungal Infections

  • Dermatophytes, such as Trichophyton rubrum, are the most common cause of onychomycosis 2, 4.
  • Yeasts, such as Candida albicans, can cause fungal infections of the nail, particularly in cases of chronic paronychia and onycholysis 2, 4.
  • Molds, such as Fusarium species, can also cause onychomycosis, particularly in cases of non-dermatophyte mold (NDM) onychomycosis 2.

Diagnosis and Treatment

  • Diagnosis of fungal infections of the nail can be confirmed by potassium hydroxide preparation, culture, or histology 6.
  • Treatment of onychomycosis typically involves the use of antifungal agents, such as terbinafine or itraconazole 2, 5, 6.
  • Topical antifungal agents, such as amorolfine or ciclopirox, can be used to treat mild cases of onychomycosis, while oral antifungal agents are typically used to treat more severe cases 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Infections of finger and toe nails due to fungi and bacteria].

Der Hautarzt; Zeitschrift fur Dermatologie, Venerologie, und verwandte Gebiete, 2014

Research

Acral manifestations of fungal infections.

Clinics in dermatology, 2017

Research

Fungal infections of the nail.

Seminars in dermatology, 1991

Research

Treating onychomycosis.

American family physician, 2001

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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