Differential Diagnosis for Brittle Fingernails with Surface Irregularities

Single Most Likely Diagnosis

• Nail Psoriasis: This condition often presents with nail changes including brittleness, pitting (small dents), and roughening of the nail surface. The appearance of small white spots could be indicative of psoriatic nail changes, which can include leukonychia (white spots due to nail plate abnormalities).

Other Likely Diagnoses

• Nutritional Deficiencies: Deficiencies in vitamins like biotin, vitamin B7, or minerals such as zinc can lead to brittle nails and surface irregularities. A diet lacking essential nutrients can impair nail health.
• Fungal Infections (Onychomycosis): While more commonly associated with thickening and discoloration of the nails, some forms of fungal infections can cause brittleness and surface changes.
• Aging: As people age, their nails can become more brittle and develop ridges or surface irregularities due to decreased nail cell growth and production.

Do Not Miss Diagnoses

• Thyroid Disorders: Both hypothyroidism and hyperthyroidism can cause changes in the nails, including brittleness and dryness. It's crucial to consider thyroid function because untreated thyroid disorders can have significant health implications.
• Systemic Lupus Erythematosus (SLE): This autoimmune disease can cause a variety of nail changes, including brittleness and surface irregularities, as part of its broader spectrum of symptoms.

Rare Diagnoses

• Sjögren's Syndrome: An autoimmune disorder that can affect the nails, among other things, causing dryness and brittleness due to decreased moisture production.
• Sarcoidosis: A condition that can affect multiple parts of the body, including the skin and nails, potentially causing nail brittleness and surface changes.
• Darier's Disease: A rare genetic disorder that affects the skin and sometimes the nails, leading to abnormalities such as red and white patches on the skin and nail changes, including brittleness.

Each of these diagnoses has a different set of implications for treatment and management, emphasizing the importance of a thorough evaluation to determine the underlying cause of the nail changes.