Woods lamp examination

Overview

A Woods lamp (or Wood's lamp) is a special black light that doctors use to examine your skin. It shines ultraviolet light, which can make certain skin infections or changes glow in different colors. It is a painless and quick test that helps with diagnosis.

A Woods lamp examination is a common diagnostic tool in dermatology (skin health). It is often used in GP surgeries and skin clinics.

Anyone can have a Woods lamp examination. It is used for people of all ages who have a skin concern, from children to older adults.

Symptoms

Common symptoms

• Patches of skin that are lighter or darker than the surrounding area.
• Flaky, scaly areas that may be itchy or red.
• Unexplained bald spots on the scalp or missing patches of body hair.

Symptoms in children

• Round, scaly patches on the scalp that may be itchy.
• Spots on the skin that glow under the lamp and do not tan in the sun.
• Pale patches that appear after a rash or infection.

Symptoms in older adults

• Changes in skin color or texture that are new or spreading.
• Sores or rashes that do not heal quickly.
• Increased pigmentation or loss of pigment in sun-exposed areas.

Causes

Main causes

• Fungal infections like ringworm (tinea) that glow under the lamp.
• Bacterial infections like erythrasma that have a coral-red glow.
• Pigment disorders such as vitiligo (loss of skin color) or melasma (dark patches).

Risk factors

• Having a weakened immune system (for example from illness or medicines).
• Being in close contact with someone who has a fungal infection.

When to see a doctor

See a doctor urgently if:

• If you have a rapidly spreading rash with pain, fever, or blistering.
• If you develop a skin infection after an injury or surgery that looks worse quickly.

Book a routine appointment if:

• If you have a persistent skin discoloration or patch that does not go away after a few weeks.
• If you notice a new spot that changes in size, shape, or color.
• If you have scaling or itching that over-the-counter creams do not relieve.

Diagnosis

A Woods lamp examination is done in your doctor's office or clinic. The room lights are dimmed, and the doctor shines the special lamp close to your skin. They will look for any glowing areas, which can indicate an infection or other skin condition.

Tests that may be done

• Woods lamp examination.
• Sometimes a skin scraping is taken for microscopy or culture to confirm the cause.

What to expect at your appointment

The test takes a few minutes. You will be asked to remove any makeup or lotions from the area. The lamp does not hurt or cause any harm. After the test, your doctor will discuss what the findings mean and if any further tests or treatment are needed.

Treatment

Treatment depends on what the Woods lamp examination finds. For a fungal infection, your doctor may prescribe antifungal medicine. For a bacterial infection, antibiotics might be needed. For pigment conditions like vitiligo, treatment options include creams or light therapy. Always follow your doctor's advice and use medicines exactly as directed.

Self-care at home

• Keep the affected area clean and dry.
• Avoid sharing towels, clothes, or hairbrushes if an infection is suspected.
• Wash hands after touching the area to prevent spreading.

Medical treatments

Your doctor may prescribe antifungal or antibiotic treatments, either as creams, ointments, or tablets. For pigmentation issues, treatments like topical corticosteroids or phototherapy (light treatment) may be considered. Do not use any medicine your doctor has not prescribed for you.

When is surgery considered?

Surgery is not typically needed for conditions found by a Woods lamp examination. However, in very rare cases of deep fungal infection or a growth needing removal, your doctor will explain if a procedure is required.

Living with this condition

If the Woods lamp finds a skin condition, you may need to continue treatment for several weeks. Follow your doctor's instructions carefully, and keep any follow-up appointments to make sure the condition is improving.

Lifestyle tips

• Practice good hygiene, such as washing your hands regularly and not sharing personal items.
• Avoid walking barefoot in public showers, pools, or gyms to prevent fungal infections.
• Protect your skin from the sun if you have pigmentation changes – use sunscreen and cover up.

Diet and exercise

A healthy diet rich in fruits, vegetables, and whole grains can help support your immune system. Regular exercise is good for overall health, but shower promptly after sweating to keep skin clean.

Mental health and emotional wellbeing

Having a skin condition that changes your appearance can affect your confidence or mood. It is normal to feel worried or self-conscious. Talk to your doctor or a counsellor if you are struggling, and know that many conditions are treatable.

Prevention

Many skin conditions found by a Woods lamp are not completely preventable, but you can reduce the risk of infections by practicing good hygiene. For pigmentation issues, protecting your skin from the sun and avoiding triggers like harsh skin products may help.

Complications

If left untreated

• A fungal or bacterial infection can spread to other parts of the body or to other people.
• In people with weak immune systems, infections may become more serious or harder to treat.
• Pigment conditions like vitiligo may spread or become more noticeable over time.

Long-term outlook

Most conditions found by a Woods lamp examination respond well to treatment. With proper care, fungal infections clear within weeks, and bacterial infections usually improve quickly. Pigment conditions like vitiligo may be managed over the long term. It is important to see your doctor for follow-up as needed. There is good reason to be hopeful – many people see significant improvement.

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