Psoriasis is primarily diagnosed based on its clinical features. A general practitioner (GP) can often diagnose the condition by examining the affected skin. If the diagnosis is uncertain or the condition is severe, a referral to a dermatologist may be necessary. In rare cases, a skin biopsy may be performed to confirm the diagnosis. Additionally, if psoriatic arthritis is suspected, a rheumatologist may be consulted, and blood tests or X-rays of affected joints might be required.
Classification
Psoriasis can be categorized based on several factors to guide appropriate treatment:
- Age of Onset: Early (<35 years) or late (>50 years)
- Type: Acute (e.g., guttate psoriasis) or chronic (e.g., plaque psoriasis)
- Location: Localized (e.g., scalp, palmoplantar) or generalized
- Plaque Size: Small (<3 cm) or large (>3 cm)
- Plaque Thickness: Thin or thick
- Nail Involvement: Presence or absence of nail psoriasis
Types of Psoriasis
- Plaque Psoriasis: The most common type, characterized by dry, itchy, raised skin patches (plaques) covered with scales.
- Nail Psoriasis: Affects fingernails and toenails, causing pitting, abnormal nail growth, and discoloration.
- Guttate Psoriasis: Often triggered by bacterial infections like strep throat, marked by small, drop-shaped scaling spots.
- Inverse Psoriasis: Affects skin folds, causing smooth, inflamed patches that worsen with friction and sweating.
- Pustular Psoriasis: Rare, characterized by pus-filled blisters.
- Erythrodermic Psoriasis: The least common, can cover the entire body with a peeling rash that itches or burns intensely.
