Onychodystrophy

Any morphologic deformity or structural abnormality of the fingernails or toenails, including changes in nail plate growth, thickness, contour, color, or integrity.

Causes

• Physical trauma

  • Repetitive pressure or friction

  • Nail biting or picking

  • Improper footwear

  • Foot deformities: Hammertoes

• Infectious causes

  • Fungal nail infection (onychomycosis)

  • Bacterial nail infections

  • Viral infections affecting periungual tissues

• Inflammatory and dermatological causes

  • Psoriasis

  • Eczema (atopic dermatitis)

  • Lichen planus

  • Alopecia areata

  • Autoimmune nail disorders

• Systemic disease causes

  • Liver failure

  • Chronic kidney disease

  • Lung disease

  • Heart disease

  • Thyroid disorders: Hypothyroidism, hyperthyroidism

  • Systemic inflammatory diseases

• Medications

  • Chemotherapy

  • Immunosuppressive

• Nutritional and metabolic causes

  • Iron deficiency

  • Zinc deficiency

  • Biotin deficiency

  • Protein deficiency

  • General malnutrition

• Congenital and genetic causes

  • Congenital nail deformities

  • Hereditary nail dystrophies

  • Genetic syndromes affecting nail development

• Aging-related growth rate reduction and increased nail thickening

• Repeated occupational exposure to chemicals

• Chronic moisture exposure