Psoriasis Symptoms: Plaques, Nails and Joints

The signature of psoriasis is a patch of thick, raised skin with silvery-white scale on top that itches or burns — most often on the scalp, elbows or knees. Nail changes and, in a substantial minority, joint pain belong to the same disease. The National Psoriasis Foundation counts more than 8 million people with psoriasis in the United States.

The symptoms

NIAMS describes the core picture as patches of thick, red skin with silvery-white scales that itch or burn, along with:

• Dry, cracked skin, which can bleed where plaques are thickest
• Thick, ridged, pitted nails
• Sleep disturbance, from the itch and discomfort
• Pain or tenderness in the affected skin

Plaques are sharply bordered — you can usually trace where they stop — and sit higher than the skin around them. On brown and black skin the same plaques typically look violet, gray or dark brown rather than red, with the scale sometimes appearing gray.

The five types and what each looks like

• Plaque psoriasis — the most common form by a wide margin, affecting the scalp, trunk and limbs with the classic thick, scaly patches.
• Guttate psoriasis — small red dots scattered over the skin, often appearing after an upper respiratory infection, particularly a streptococcal one.
• Pustular psoriasis — pus-filled bumps, which may follow stress or exposure to certain chemicals. The pus is sterile; this is not an infection.
• Inverse psoriasis — smooth patches in skin folds, such as the armpits, groin and under the breasts, where friction and moisture keep the scale from forming.
• Erythrodermic psoriasis — a rare, severe form affecting most of the body surface, which is a medical emergency rather than a cosmetic problem.

Nail psoriasis

Nail involvement is common and can precede any obvious skin disease. NIAMS lists thick, ridged and pitted nails; the pitting looks like the nail was struck repeatedly with a pin. Nails may also separate from the nail bed or discolor. Because nail psoriasis is easily mistaken for a fungal infection, it is one of the most frequently mistreated presentations — see fungal skin infection symptoms for the contrast.

When the joints get involved

Psoriatic arthritis causes pain, swelling and stiffness of the joints, and NIAMS warns it can lead to irreversible damage if left untreated. The National Psoriasis Foundation estimates about 30 percent of people with psoriasis develop it — roughly 2.4 million Americans. Morning stiffness that lasts, a swollen finger or toe, or heel pain in someone with psoriasis is a reason to raise it with a doctor rather than wait.

What triggers a flare

NIAMS names infections — especially streptococcal infection and HIV — certain medications, smoking, and obesity. Guttate flares in particular tend to follow an upper respiratory infection, and pustular flares can follow stress or chemical exposure. Skin injury, including cuts, scrapes and sunburn, can bring plaques up at the injured site.

Psoriasis or eczema

The two are confused constantly, and a few features separate them reasonably well:

Feature	Psoriasis	Eczema
Border	Sharply defined	Diffuse, fading into normal skin
Scale	Thick, silvery-white	Fine, or absent
Favorite sites	Scalp, elbows, knees, lower back	Bends of elbows and knees, neck, hands
Nails	Pitting and separation are common	Rarely involved
Itch	Present, often with burning	Usually the dominant complaint

For the other side of that comparison, see eczema symptoms.

What to do

1. Get a diagnosis before a treatment plan. Thick scaly plaques have several possible causes, and the treatments do not overlap.
2. Moisturize consistently to reduce cracking and the discomfort of scale.
3. Do not pick or force scale off. It worsens inflammation and can trigger new plaques at the injured site.
4. Address the modifiable triggers — smoking and weight are on the NIAMS list for a reason.
5. Report joint symptoms early, because damage from psoriatic arthritis does not reverse.

When to push for more

See a dermatologist if plaques cover a large area, if the scalp or nails are involved, if you have joint pain or stiffness, or if the condition is affecting your sleep, work or how you feel about being seen. Extensive or resistant psoriasis has many more options than topical cream, and “managing” it badly for years is not a necessary outcome.

This content is informational and does not replace a medical consultation, diagnosis, or treatment. See also common skin conditions and dermatitis symptoms.