Psoriasis and dry scaly rashes

Psoriasis is a long term inflammatory skin condition that causes red, thickened patches of skin with silvery scale. Dry scaly rashes can also occur due to other skin conditions, including eczema, fungal infections, or irritation.

This page explains how psoriasis differs from other scaly rashes, what causes flare ups, and when to seek GP review.

These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help with skin concerns, please book an appointment. We also offer specialist GP dermatology input at the Skin Clinic.

Skin Clinic

Eczema vs psoriasis: what is the difference?

Eczema and psoriasis can look similar, but they are different conditions and are managed in different ways.

Eczema (dermatitis) is mainly caused by a weakened skin barrier and an over-sensitive immune response. This leads to dry, itchy, inflamed skin that is often less well defined and may weep or crust during flare ups. It commonly affects skin folds, hands, face, and behind the knees.

Psoriasis is an immune mediated condition where skin cells are produced too quickly. This causes thicker, well defined red patches with white or silvery scale, often on the elbows, knees, scalp, and lower back. Some people also develop nail changes or joint pain.

Symptoms of psoriasis and scaly rashes

Psoriasis commonly causes:

Well defined red patches of skin
Thick white or silvery scale
Dry or cracked skin that may bleed
Itching or soreness
Flare ups followed by periods of improvement

Psoriasis often affects the elbows, knees, scalp, lower back, and nails. Some people also develop joint pain linked to psoriasis.

Other dry scaly rashes may be less well defined and vary in appearance depending on the cause.

Common causes and triggers

Psoriasis

Psoriasis is an immune mediated condition where skin cells are produced too quickly. It is not contagious.

Triggers may include:

Stress
Infections such as sore throats
Cold weather
Skin injury
Certain medications

Other dry scaly rashes

Dry scaly rashes can also be caused by:

Eczema or dermatitis
Fungal skin infections
Seborrhoeic dermatitis
Very dry skin

Correct diagnosis is important, as treatments differ.

How a GP assesses psoriasis

A GP will assess psoriasis based on appearance, distribution, and history. During an assessment, they may ask about:

Age of onset and family history
Pattern and frequency of flare ups
Nail changes or joint pain
Current treatments and response
Impact on daily activities or wellbeing

Photographs are usually sufficient for remote assessment.

Investigations

Most people with psoriasis do not need tests.

Blood tests or referral may be considered if joint symptoms suggest psoriatic arthritis or if systemic treatment is being considered.

Self care and lifestyle measures

Self care can help reduce flare ups and improve comfort:

Use emollients daily to reduce dryness and scaling
Avoid harsh soaps and fragranced products
Keep skin moisturised, especially after bathing
Manage stress where possible
Avoid picking or scratching plaques

Regular moisturising supports the skin barrier and improves treatment response.

When to seek urgent medical advice

Seek urgent medical advice if:

Skin becomes painful, hot, or rapidly worsening
There are signs of widespread infection
You develop new joint swelling or severe joint pain

Medical treatments a GP may recommend

Treatment depends on severity and area affected. A GP may recommend:

Topical steroid preparations
Vitamin D based creams or ointments
Tar based treatments in selected cases
Treatments for scalp or nail involvement

Moderate or severe psoriasis may require referral for specialist input.

When to seek GP review

You should consider a GP appointment if:

Scaly rashes are persistent or worsening
Psoriasis is spreading or painful
Symptoms are affecting sleep, mood, or daily life
You have nail changes or joint pain
Over the counter treatments are not helping

Early review helps optimise treatment and reduce complications.