Managing a persistent skin condition can be challenging, particularly when symptoms continue despite regular treatment. Conditions such as eczema and psoriasis may cause recurring inflammation, itching and discomfort that affect daily activities and sleep.

While creams and medications are commonly used to manage these conditions, they may not provide sufficient relief for everyone. In certain situations, a dermatologist may recommend phototherapy as an additional treatment option.

Understanding when phototherapy may be considered, what it involves and its potential risks can help patients make informed decisions about their skin care.

What Is Phototherapy?

Phototherapy, also known as light therapy, is a medical treatment that uses controlled exposure to ultraviolet (UV) light to manage certain skin conditions. Unlike natural sunlight, medical phototherapy delivers measured doses of specific UV wavelengths under clinical supervision.

The treatment works by influencing immune activity in the skin, helping to reduce inflammation and slow excessive skin cell growth.

One commonly used method is narrowband ultraviolet B (NB-UVB) therapy, which uses a selected range of UV wavelengths. Another approach, known as PUVA, combines ultraviolet A (UVA) light with a light-sensitising medication called psoralen.

The type of phototherapy recommended depends on the skin condition, medical history and individual treatment needs.

Which Skin Conditions May Be Treated With Phototherapy?

Phototherapy may be considered for several skin conditions, particularly those involving chronic inflammation or changes in skin pigmentation.

Eczema (Atopic Dermatitis)

Eczema can cause dry, inflamed and itchy skin. For individuals with moderate to severe eczema that does not respond adequately to appropriate topical treatment, phototherapy may help manage inflammation and reduce symptoms.

Psoriasis

Psoriasis is a chronic inflammatory condition that causes skin cells to build up more quickly than usual, resulting in thickened, scaly patches. Phototherapy may help reduce inflammation and slow excessive skin cell production, particularly when psoriasis affects larger areas of the body.

Vitiligo

Vitiligo occurs when areas of skin lose their natural pigmentation. Certain forms of phototherapy may stimulate pigment-producing cells and support repigmentation in some patients. However, treatment response varies depending on factors such as the location and extent of the affected skin.

Phototherapy may also be used for selected other dermatological conditions, although its suitability depends on the diagnosis and clinical circumstances.

When Might a Dermatologist Recommend Phototherapy?

Not every persistent skin condition requires light therapy. Dermatologists generally consider several factors before recommending it, including symptom severity, treatment history and how the condition affects daily life.

A dermatologist in Singapore may discuss phototherapy in the following situations:

When Topical Treatments Are Not Providing Enough Relief

Moisturisers, topical corticosteroids and other prescribed creams are commonly used to manage inflammatory skin conditions. However, some patients continue to experience symptoms despite following an appropriate treatment plan.

For example, someone with eczema may continue to experience frequent flare-ups or persistent itching even after using prescribed topical treatments. In these cases, a dermatologist may assess whether phototherapy or another treatment option is appropriate.

When a Skin Condition Affects Large Areas of the Body

Applying topical medication to extensive areas of skin can be difficult, especially when inflammation affects multiple regions.

Phototherapy may be considered when widespread eczema or psoriasis requires additional treatment beyond topical medication alone. The decision depends on the severity of the condition and the patient’s overall health.

When Symptoms Continue to Affect Daily Activities

Persistent itching, scaling and inflammation can interfere with sleep, work and everyday activities.

If symptoms remain troublesome despite treatment, a dermatologist may review the current management approach and consider whether phototherapy could help improve disease control.

When Other Treatment Options May Not Be Suitable

Some patients may be unable to use certain medications because of side effects, medical conditions or potential interactions with other treatments.

Phototherapy may provide an alternative for selected individuals. However, it also carries risks and requires an assessment of potential contraindications before treatment begins.

How Does a Dermatologist Determine Whether Phototherapy Is Suitable?

Before recommending phototherapy, a dermatologist will usually review the patient’s medical history, symptoms and previous treatments.

This assessment may involve examining the affected skin, confirming the diagnosis and evaluating the extent of the condition. The dermatologist may also ask about medications, supplements and any previous reactions to sunlight.

Certain conditions, including some photosensitivity disorders and a history of particular skin cancers, may affect whether UV-based treatment is appropriate.

The patient’s ability to attend repeated sessions is another important consideration. Since phototherapy usually requires treatment over several weeks, regular attendance may influence whether it is a practical option.

A dermatologist will weigh these factors alongside alternative treatments before recommending an individual management plan.

What Can Patients Expect If Phototherapy Is Recommended?

Patients undergoing phototherapy are exposed to controlled doses of ultraviolet light using specialised medical equipment.

Depending on the treatment prescribed, patients may stand inside a light cabinet or receive treatment directed at specific areas of the skin. Protective eyewear and coverings may be required to shield areas that do not need exposure.

Treatment is commonly scheduled two to three times per week initially, although the frequency varies according to the condition and treatment protocol.

Individual sessions may be relatively brief, but repeated appointments are usually necessary before improvements become noticeable. The total treatment course depends on how the skin responds.

During treatment, the dermatologist may adjust the UV dose and monitor the patient’s progress. Some individuals may also need to continue prescribed topical treatments alongside phototherapy.

Phototherapy is used to manage symptoms rather than permanently cure chronic skin conditions, and further treatment may be needed if symptoms return.

What Are the Potential Risks and Precautions of Phototherapy?

Although phototherapy is an established dermatological treatment, exposure to ultraviolet light can cause side effects.

Some patients may experience temporary redness, dryness, itching or skin tenderness after treatment. More pronounced reactions, including sunburn-like irritation or blistering, can also occur.

Repeated UV exposure may contribute to premature skin ageing. Skin cancer risk is another consideration, particularly with higher cumulative UV exposure and certain treatment types, such as PUVA.

Before starting treatment, patients should inform their dermatologist about any medications or supplements they take, as some substances can increase sensitivity to UV light.

Patients may also be advised to limit additional sun exposure during treatment and follow specific skin protection instructions.

Any persistent burning, significant redness, blistering or unusual skin reactions should be reported to the treating medical team.

What Should Patients Discuss Before Starting Phototherapy?

Patients considering phototherapy may find it helpful to discuss their treatment goals and expectations with a dermatologist.

Important questions include whether phototherapy is appropriate for their specific condition, how frequently sessions may be needed and what changes they can reasonably expect.

Patients should also ask about potential side effects, necessary precautions and whether existing medications or skincare products should be continued.

Understanding the treatment schedule and the possibility of future flare-ups can help patients decide whether phototherapy fits their circumstances.

Phototherapy may be considered for individuals with certain persistent or widespread skin conditions, particularly when topical treatments have not provided adequate symptom control. It can form part of a broader management plan for conditions such as eczema, psoriasis and vitiligo.

However, treatment suitability varies between patients. The diagnosis, severity of symptoms, previous treatments, medical history and potential risks all influence whether phototherapy is an appropriate option.

For individuals experiencing ongoing skin concerns, a dermatological assessment can help clarify the available treatments and determine whether phototherapy should be considered as part of their care.

Medical disclaimer: This article is intended for general educational purposes and does not replace professional medical advice, diagnosis or treatment. Patients should consult a qualified healthcare professional for advice appropriate to their condition.