Differential Diagnosis for Nail Bed Pitting
Single Most Likely Diagnosis
- Psoriasis: Nail pitting is a common finding in psoriasis, affecting up to 50% of patients. The pitting is due to the involvement of the nail matrix, leading to the formation of small depressions on the nail surface.
Other Likely Diagnoses
- Alopecia Areata: This autoimmune condition can cause nail pitting, among other nail changes, due to inflammation of the nail matrix.
- Eczema (Dyshidrotic Eczema): While less common, eczema can lead to nail changes, including pitting, especially if the nail matrix is involved.
- Reactive Arthritis (Reiter's Syndrome): This form of arthritis can cause nail pitting as part of its spectrum of symptoms, which also includes arthritis, urethritis, and conjunctivitis.
Do Not Miss Diagnoses
- Sarcoidosis: Although rare, sarcoidosis can cause nail pitting among its myriad of other systemic symptoms. Missing this diagnosis could lead to delayed treatment of a potentially serious condition.
- SLE (Systemic Lupus Erythematosus): Nail pitting can be a part of the nail changes seen in SLE. Given the potential severity of SLE, it's crucial not to miss this diagnosis.
Rare Diagnoses
- Lichen Planus: While primarily known for its skin and mucous membrane manifestations, lichen planus can rarely cause nail changes, including pitting.
- Nail Patella Syndrome: A rare genetic disorder characterized by nail abnormalities (including pitting), patellar aplasia, and other systemic features.
- Sjögren's Syndrome: An autoimmune disorder that can cause nail pitting among its other symptoms, primarily dry eyes and dry mouth.