What Is Psoriasis?Scaly Patches and the Joint Pain to Watch For

It started as a dry patch on your elbow, and the cream didn’t touch it. Then there was one on your scalp that looked like dandruff, only thicker, with silvery flakes that fall on your black sweater. It itches, and sometimes it stings. You’re wondering if it’s eczema, or a fungus, or something you caught.

What it looks like

The NHS³ describes itchy, painful patches of dry, flaky skin with silvery-white scales, typically 1 to 2 cm, pink or red on light skin and grey on darker skin, on the head, chest, limbs and skin folds. Nails may show dents and pits. The AAD² says plaque psoriasis affects 80 to 90% of patients, and that itch can become intense, with stinging, burning or tightness. It lists the knees, elbows, lower back and scalp as common spots.

The NIAMS¹ lists five types: plaque, guttate (small red dots, often after strep throat), pustular (pus-filled bumps), inverse (smooth patches in skin folds) and erythrodermic, a rare severe form covering most of the body. See eczema and an itchy, flaky scalp.

What sets it off

The NIAMS¹ says it involves a combination of genetics and environmental factors, with external triggers including infections such as strep and HIV, certain medicines, smoking and obesity. The NHS³ lists stress, alcohol, smoking, obesity, pregnancy, some medicines, infections like strep A, skin injuries and sun exposure.

Treatment

The NIAMS¹ says mild psoriasis can often be treated with creams or ointments, while moderate and severe cases may need pills, injections or light treatments. The NHS³ lists vitamin D preparations, emollients, steroid creams, coal tar products, light therapy and systemic medicines, and says a GP can prescribe some or refer you to a dermatologist. The AAD² says managing psoriasis means learning and avoiding triggers, keeping a skincare routine, living healthily and using medication when needed.

The joints

The NIAMS¹ says psoriatic arthritis is a serious complication, with pain, swelling and stiffness of the joints that can lead to irreversible damage if untreated. The NHS³ says to seek care for pain, stiffness and swelling in your joints that keeps coming back. The AAD² says a dermatologist can also monitor for associated conditions like psoriatic arthritis or diabetes. See joint aches in menopause for a different cause of joint pain.

The play

Try this: a flare diary and photo log

For a month, take a photo of each patch weekly in the same light, and write down itch from 1 to 10, new patches and what changed: stress, illness, a new medicine, alcohol, sun, skin injury.

Add any joint pain, morning stiffness or nail changes.

Bring it to your appointment. A dermatologist can match treatment to the pattern.

When to get checked

Don’t wait if

1. Emergency

   The NHS³ says to see a GP if you have psoriasis symptoms, if treatment isn’t working or if you develop joint symptoms, and to call emergency services if the skin rapidly turns red with pus-filled bumps or you have other serious signs. The AAD² says to see a board-certified dermatologist because psoriasis is typically lifelong.

2. Emergency

   Get emergency care if the skin turns red rapidly with pus-filled bumps.

Book an appointment if any of these fit:

• You have thick, silvery, itchy patches that aren’t going away
• Your scalp or nails have changed
• Joints are painful, stiff or swollen, and it keeps coming back
• Treatment you’ve been using isn’t working
• You’re not sure whether it’s psoriasis or eczema
• The patches are spreading

The AAD² calls psoriasis typically lifelong. A dermatologist can help you manage it, and keep an eye on your joints.