Causes and Risk Factors
Psoriasis develops when the immune system mistakenly attacks healthy skin, speeding up skin cell turnover from about a month to just a few days. Several factors influence who develops psoriasis and when it flares:- Genetics: Having a parent or sibling with psoriasis significantly increases your risk of developing it.
- Infections: Strep throat and other infections can trigger a first outbreak or a flare, particularly in children and young adults.
- Skin injury: Cuts, scrapes, sunburns, and even tattoos can spark new plaques at the site of injury, a response called the Koebner phenomenon.
- Stress and lifestyle: Emotional stress, smoking, heavy alcohol use, and cold, dry weather are common flare triggers.
- Medications: Certain drugs, including lithium and some blood pressure medicines, can bring out or worsen psoriasis.
Symptoms
Psoriasis looks different from person to person, but common signs include:- Raised plaques with silvery scale: Most often on the elbows, knees, scalp, and lower back, though any skin surface can be involved.
- Itching, burning, or soreness: Discomfort ranges from mild to intense, and scratching can worsen the plaques.
- Nail changes: Pitting, thickening, discoloration, or lifting of the fingernails and toenails.
- Different patterns: Plaque psoriasis is the most common form, but guttate psoriasis causes small, drop-shaped spots after infections, inverse psoriasis affects skin folds, and some people have mainly scalp or nail disease.
- Joint pain and stiffness: Up to one in three people with psoriasis develops psoriatic arthritis, a form of inflammatory arthritis that can damage joints if untreated.
Diagnosis
Most psoriasis is diagnosed by its appearance during a careful skin examination, including a look at the scalp and nails. Occasionally a small skin biopsy is needed to distinguish it from look-alike rashes such as dermatitis or a fungal infection. Your clinician will also gauge severity by estimating how much of the body surface is involved and asking how symptoms affect sleep, work, and mood, since those answers guide treatment choices.Treatment
Treatment is tailored to how much skin is involved and how much psoriasis affects your daily life:- Topical therapy: Corticosteroid creams and vitamin D analog ointments are the usual first step for limited plaques.
- Phototherapy: Carefully dosed ultraviolet light treatments delivered in a medical setting can calm widespread disease.
- Oral medications: Newer pills such as apremilast and deucravacitinib quiet the immune signals that drive plaque formation.
- Biologic medications: Injectable agents that block specific immune pathways — including secukinumab, ixekizumab, brodalumab, guselkumab, risankizumab, and tildrakizumab — can clear even severe psoriasis for many patients.