Model Answer
0 min readIntroduction
Psoriasis is a chronic, immune-mediated inflammatory skin disease characterized by raised, red, scaly patches. It affects approximately 1-3% of the global population, with a peak onset between 16 and 54 years of age. While the exact etiology remains unclear, a genetic predisposition combined with environmental triggers is believed to play a significant role. The clinical presentation of psoriasis is highly variable, ranging from localized, mild disease to widespread, severe involvement. Understanding these diverse clinical features is crucial for accurate diagnosis and appropriate management. This answer will detail the clinical features of the most common types of psoriasis.
Clinical Features of Psoriasis – Based on Type
Psoriasis manifests in several distinct forms, each with unique clinical characteristics.
1. Plaque Psoriasis (Psoriasis Vulgaris)
- Appearance: Well-defined, erythematous (red) plaques covered with silvery-white scales.
- Distribution: Commonly affects extensor surfaces (elbows, knees), scalp, lower back, and nails.
- Symptoms: Pruritus (itching) is common, but not always present. Plaques can be painful, especially if fissured.
- Koebner Phenomenon: New lesions develop at sites of skin trauma (e.g., scratches, cuts).
2. Guttate Psoriasis
- Appearance: Small, drop-like papules (1-10 mm in diameter) scattered across the trunk and limbs.
- Association: Often triggered by a preceding streptococcal throat infection.
- Symptoms: Usually mildly symptomatic, with minimal itching.
- Prognosis: Often self-limiting, but can progress to plaque psoriasis in some cases.
3. Inverse Psoriasis (Flexural Psoriasis)
- Appearance: Smooth, red, inflamed patches in skin folds (armpits, groin, under breasts).
- Characteristics: Lacks the typical silvery scales seen in plaque psoriasis due to the moist environment.
- Symptoms: Intense itching and discomfort, exacerbated by friction and sweating.
4. Pustular Psoriasis
- Appearance: Characterized by sterile pustules (small blisters filled with pus) surrounded by erythematous skin.
- Types:
- Localized Pustular Psoriasis: Affects palms and soles.
- Generalized Pustular Psoriasis: Rare and severe form with widespread pustules and systemic symptoms (fever, malaise).
- Symptoms: Painful and often accompanied by systemic illness.
5. Erythrodermic Psoriasis
- Appearance: Widespread, fiery-red inflammation affecting most of the body surface.
- Characteristics: Skin appears shiny and scaly, with significant shedding.
- Symptoms: Severe itching, burning, and pain. Can lead to dehydration, electrolyte imbalance, and hypothermia.
- Severity: This is a medical emergency requiring immediate treatment.
6. Nail Psoriasis
- Appearance: Pitting (small depressions) of the nail plate is the most common finding.
- Other features: Onycholysis (separation of the nail from the nail bed), subungual hyperkeratosis (thickening under the nail), oil drop sign (yellowish discoloration under the nail).
- Symptoms: Nail pain and distortion.
| Psoriasis Type | Key Clinical Features | Common Distribution |
|---|---|---|
| Plaque Psoriasis | Erythematous plaques with silvery scales, Koebner phenomenon | Extensor surfaces, scalp, lower back |
| Guttate Psoriasis | Small, drop-like papules | Trunk and limbs |
| Inverse Psoriasis | Smooth, red patches | Skin folds (armpits, groin) |
| Pustular Psoriasis | Sterile pustules | Palms/soles (localized), widespread (generalized) |
| Erythrodermic Psoriasis | Widespread erythema and scaling | Most of body surface |
Conclusion
Psoriasis presents with a diverse range of clinical features, varying significantly based on the type and severity of the disease. Accurate diagnosis relies on recognizing these characteristic presentations, including the morphology of lesions, their distribution, and associated symptoms. Early and appropriate management is crucial to improve quality of life and prevent complications. Further research into the pathogenesis of psoriasis continues to refine treatment strategies and improve patient outcomes.
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.