Model Answer
0 min readIntroduction
Psoriasis is a chronic, immune-mediated inflammatory skin disease affecting approximately 1-3% of the population worldwide. While commonly recognized for its skin lesions, psoriasis frequently involves the nails in up to 80% of patients, significantly impacting quality of life. Nail psoriasis can be the sole manifestation of the disease, making its recognition crucial for early diagnosis and management. The nail changes are often subtle and can mimic other nail disorders, necessitating a thorough clinical examination. This answer will detail the characteristic nail findings observed in individuals with psoriasis.
Nail Findings in Psoriasis
Nail psoriasis presents with a diverse range of findings, often affecting multiple nails simultaneously. These changes can be broadly categorized as follows:
1. Pitting
- Description: Small, pinpoint depressions on the nail surface. This is one of the most common findings, occurring in up to 56% of patients with nail psoriasis.
- Pathogenesis: Caused by defective keratinization of the nail matrix.
- Clinical Significance: While highly suggestive, pitting is not pathognomonic for psoriasis and can be seen in other conditions like alopecia areata and trauma.
2. Onycholysis
- Description: Separation of the nail plate from the nail bed, typically starting distally. It appears as a white or yellowish discoloration under the nail.
- Pathogenesis: Resulting from subungual hyperkeratosis and inflammatory processes disrupting the nail bed adhesion.
- Clinical Significance: Can be a significant cosmetic concern and predispose to secondary infections.
3. Subungual Hyperkeratosis
- Description: Accumulation of keratin beneath the nail plate, causing thickening and lifting of the nail.
- Pathogenesis: Increased rate of keratin production due to inflammation.
- Clinical Significance: Contributes to onycholysis and can be painful.
4. Oil Drop Sign (Salmon Patch)
- Description: Yellowish-red discoloration under the nail plate, resembling a drop of oil.
- Pathogenesis: Caused by accumulation of keratin and parakeratosis beneath the nail plate, obscuring the underlying nail bed vasculature.
- Clinical Significance: Highly suggestive of psoriasis, though not always present.
5. Nail Plate Thickening & Distortion
- Description: The nail plate becomes abnormally thick and can be distorted in shape.
- Pathogenesis: Chronic inflammation and hyperkeratosis.
- Clinical Significance: Can lead to difficulty in nail care and increased risk of trauma.
6. Splinter Hemorrhages
- Description: Thin, longitudinal lines of blood under the nail plate.
- Pathogenesis: Damage to the nail bed capillaries, often associated with inflammation.
- Clinical Significance: Can also be seen in trauma, endocarditis, and other conditions.
7. Chromonychia
- Description: Discoloration of the nail plate, ranging from yellow to brown or black.
- Pathogenesis: Can be due to various factors, including fungal infection, medication, or underlying inflammation.
- Clinical Significance: Requires careful evaluation to rule out other causes.
Table summarizing Nail Findings in Psoriasis:
| Finding | Description | Prevalence (approx.) |
|---|---|---|
| Pitting | Pinpoint depressions on nail surface | 56% |
| Onycholysis | Nail plate separation from nail bed | 30-50% |
| Subungual Hyperkeratosis | Keratin accumulation under nail plate | 30-60% |
| Oil Drop Sign | Yellowish-red discoloration under nail | 10-30% |
| Nail Plate Thickening | Abnormal nail plate thickness | 20-40% |
It's important to note that the severity and combination of these findings can vary significantly between individuals. Nail psoriasis can also be associated with other psoriatic features, such as skin lesions, joint pain (psoriatic arthritis), and scalp involvement.
Conclusion
Nail psoriasis presents a diagnostic challenge due to the varied and often subtle nature of its manifestations. Recognizing the characteristic findings – pitting, onycholysis, subungual hyperkeratosis, and the oil drop sign – is crucial for accurate diagnosis. Early identification and appropriate management are essential to prevent disease progression, minimize complications, and improve the patient’s quality of life. A thorough clinical examination, coupled with consideration of other psoriatic features, is paramount in establishing a definitive diagnosis.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.