What is the cause of koilonychia (nail spooning)?

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From the Research

Nail spooning, or koilonychia, is a condition that should prompt investigations for iron deficiency, as it is frequently observed in chronic iron deficiency secondary to malnutrition, chronic blood loss, or malabsorption 1. The condition is characterized by thin, brittle, and spoon-shaped nails, and its presence may indicate an underlying health issue.

  • The most common cause of nail spooning is iron deficiency anemia, which should be addressed with iron supplementation, typically ferrous sulfate 325mg taken once or twice daily with vitamin C to enhance absorption.
  • Other potential causes include hemochromatosis, lupus, thyroid disorders, or trauma to the nail.
  • If you notice nail spooning, seek medical evaluation for proper diagnosis through blood tests, particularly a complete blood count and iron studies.
  • While treating the underlying cause, protect your nails from trauma and chemicals, keep them trimmed short, and avoid harsh nail products. Nail spooning occurs because low iron levels affect keratin production, which is essential for proper nail formation, as noted in a study on koilonychia 2.
  • The nail matrix produces thinner, weaker nail plates that gradually curve upward at the edges, creating the characteristic spoon shape.
  • With appropriate treatment of the underlying condition, nail appearance typically returns to normal within several months as new, healthy nail tissue grows. It is essential to be aware of the potential cutaneous and systemic associations with koilonychia to guide appropriate workup, treatment, and/or referral, as discussed in a comprehensive review of the condition 2.

References

Research

Spoon nails: still seen in today's world.

Clinical case reports, 2018

Research

Koilonychia: an update on pathophysiology, differential diagnosis and clinical relevance.

Journal of the European Academy of Dermatology and Venereology : JEADV, 2016

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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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