Nail Psoriasis
Nail involvement is common in psoriasis patients and often serves as a clinical marker for Psoriatic Arthritis. It results from psoriasis affecting the nail matrix and nail bed.
Key Clinical Findings
| Finding | Description |
|---|---|
| Pitting | Small, punctate depressions in the nail plate (matrix involvement). |
| Onycholysis | Separation of the nail plate from the nail bed (nail bed involvement). |
| Oil Drop Sign | Translucent, yellow-red discoloration under the nail plate. |
| Hyperkeratosis | Thickening of the nail bed, often causing the nail to lift. |
Clinical Significance
- Arthritis Association: Nail changes are strongly associated with distal interphalangeal (DIP) joint arthritis in psoriatic arthritis.
- Differential Diagnosis: Always rule out Onychomycosis (fungal infection) via KOH preparation or nail clippings for PAS staining, as treatments for psoriasis can worsen fungal infections.
High-Yield Exam Pearl:
- Management: Challenging to treat. Intralesional corticosteroids can be effective but painful. Systemic therapies (biologics like TNF inhibitors or IL-17/IL-23 inhibitors) are often required for refractory disease associated with arthritis.