Psoriasis is a chronic immune-driven disease in which skin cells grow too fast and build up into thick, scaly red plaques. It often runs in families, can affect the nails and joints, and is linked to heart disease, diabetes and depression.
Key symptoms
- Thick, red, scaly patches on the elbows, knees, scalp and lower back
- Itching, cracking or bleeding of the plaques
- Pitted or crumbling nails
- Joint pain, morning stiffness or a swollen finger or toe
- Flares with stress, infection, alcohol or some medicines
What you find on exam
- Well-defined red plaques with silvery scale
- Pinpoint bleeding when scale is removed (Auspitz sign)
- New lesions at sites of skin injury (Koebner phenomenon)
- Nail pitting, oil-drop spots and nail lifting
- Joint exam for psoriatic arthritis: swelling, sausage digits, tender tendon insertions
Tests
- Diagnosis is clinical; biopsy if unclear
- Throat swab for strep in guttate psoriasis
- Screen blood pressure, lipids, glucose and weight
- Before biologics: TB test, hepatitis B and C, blood count and liver tests
Treatment basics
- Mild disease: topical steroids, a vitamin D analog such as calcipotriene, moisturizers
- Moderate to severe: narrowband UVB phototherapy or methotrexate
- Biologics such as adalimumab, secukinumab or ustekinumab, or oral apremilast
- Avoid oral steroids, which can trigger a severe flare when stopped
- Manage joint disease, heart risk factors and mood
Red flags
- Red skin over most of the body with chills (erythrodermic psoriasis)
- Sudden widespread pustules with fever (pustular psoriasis)
- Swollen, damaged joints, or signs of infection while on biologics
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.