Pityriasis Versicolor: Symptoms, Causes, and UK Treatment Options

Pityriasis versicolor, also frequently referred to as tinea versicolor, is a common and harmless fungal infection of the skin. It occurs when a type of yeast called Malassezia, which normally lives on the skin surface without causing issues, begins to grow uncontrollably. This overgrowth disrupts the normal pigmentation of the skin, resulting in characteristic små, flat patches that may be lighter or darker than the surrounding skin.

In the UK, this condition is most frequently seen in teenagers and young adults, often becoming more noticeable during the summer months or after holidays to warmer climates. This is because the yeast flourishes in warm, moist environments, and the discoloured patches do not tan when exposed to sunlight, making them stand out more against sun-kissed skin.

It is important to note that pityriasis versicolor is not contagious; you cannot catch it from someone else, nor can you pass it on through physical contact or sharing items like towels. It is strictly a result of the yeast already present on your own body becoming overactive.

The primary symptom of pityriasis versicolor is the appearance of small, oval-shaped patches on the skin. These patches typically occur on the trunk (the chest and back), upper arms, or neck. In some cases, they may also appear on the belly or thighs.

Key characteristics of these patches include:

• Colour variation: Patches can be pink, red, pale brown, or white. In people with darker skin tones, they often appear lighter (hypopigmentation), whereas in paler skin, they may appear darker.
• Texture: The skin may feels slightly scaly or dry in the affected areas.
• Itching: While many people have no sensations at all, some report mild itching, particularly when they get hot or sweaty.
• Sunlight reaction: One of the most common ways people notice the condition is when the patches fail to tan, creating a mottled appearance after sun exposure.

The patches may start small but can merge together to cover larger areas of the body if left untreated. Unlike other fungal infections like ringworm, pityriasis versicolor does not usually cause highly inflamed, raised edges or intense discomfort.

The yeast responsible for pityriasis versicolor is a natural part of the human skin microbiome. Factors that can trigger the overgrowth of Malassezia yeast include:

• Warm and humid weather: Excess heat encourages the yeast to multiply.
• Oily skin: The yeast feeds on the natural oils (sebum) produced by your skin.
• Heavy sweating: Exercise or living in a tropical climate can create the moist environment the fungus prefers.
• Hormonal changes: This explains why the condition is more prevalent during adolescence and young adulthood.
• Weakened immune system: Individuals with certain health conditions or those taking medications that suppress the immune system may be more prone to flares.

NICE guidance suggests that while anyone can develop the condition, it is rarely seen in young children or the elderly unless there are underlying health factors. While it is not related to poor hygiene, keeping the skin cool and dry can help manage the symptoms.

If you notice persistent, discoloured patches on your skin that you suspect may be pityriasis versicolor, seeking a professional consultation is the best next step. While the condition is not dangerous, it can be persistent and emotionally distressing due to its appearance.

You should consider speaking to a GP or using an online doctor service in the UK if:

• Over-the-counter (OTC) antifungal treatments from a pharmacy have not worked after several weeks.
• The rash is spreading rapidly across larger areas of your body.
• The patches are causing significant itching or discomfort.
• The appearance is affecting your confidence or mental wellbeing.
• The rash has returned after previously being treated.

An online consultation allows you to share photos of the affected area with an experienced clinician. They can often provide a diagnosis based on visual evidence and clinical history, prescribing more effective, higher-strength treatments like ketoconazole or selenium sulfide that may not be available OTC without a prescription.

Treatment for pityriasis versicolor focuses on reducing the amount of yeast on the skin to allow the pigmentation to heal. The most common treatments used in the UK include:

Antifungal Shampoos

Medicatory shampoos such as ketoconazole (Nizoral) or selenium sulfide (Selsun) are frequently prescribed. These are applied to the affected skin, left on for several minutes to penetrate the yeast, and then rinsed off. Depending on the severity, this may be done once a day for five to seven days.

Antifungal Creams

For smaller, localised areas, antifungal creams containing clotrimazole or terbinafine may be recommended. These are typically applied twice daily for several weeks.

Oral Antifungals

In stubborn or widespread cases, a GP may prescribe antifungal tablets like itraconazole. However, these are generally reserved for when topical treatments have failed, as they carry a higher risk of side effects and interactions.

Note on Recovery: It is vital to understand that while the treatment effectively kills the yeast, the discoloured patches will not disappear immediately. It can take several months for the skin to regain its uniform colour as the skin cells naturally regenerate and repigment. This does not mean the treatment has failed.

Because the yeast that causes pityriasis versicolor is always present on our skin, the condition can often return, especially during the summer months. To reduce the risk of a relapse, you can try the following:

• Prophylactic treatment: If you find the condition returns every summer, your doctor may suggest using an antifungal shampoo once every few weeks as a preventative measure.
• Avoid heavy oils: Try to use oil-free or non-comedogenic skin products and sunscreens.
• Keep cool: Wear loose, breathable cotton clothing to minimise sweating.
• Dry thoroughly: Ensure your skin is completely dry after showering or exercising.