White patches on your skin? You could be suffering from pityriasis versicolor - a yeast infection that causes a rash most commonly on your back, chest and shoulders, and presenting as a loss of pigment. It's most commonly spotted in summer when skin is tan. Which also happens to be when you have the most skin out... ideal.
DW it's pretty common and not dangerous, but understandably an unwelcome visitor. So we're here to tell you everything you need to know about it - from what causes it, to how to detect it, and what to do if you think you've got it, according to a dermatologist.
Aesthetically, the infection looks like a loss of pigment and forms white patches on the skin, which can be itchy in some cases.
"Pityriasis versicolor is a very common yeast infection of the skin", Dr Catherine Borysiewicz, Consultant Dermatologist at the Cadogan Clinic explained. "It most commonly affects young adults. Humid weather and sweating can make the infections more commonly seen. It usually goes undetected on the skin in winter months and is noticed more frequently in the summer months.
"The rash typically consists of slightly scaly patches on the skin of the back, chest, neck and arms. It is usually not itchy, but some patients do report a mild itch and dermatitis. The rash can have a number of different colours, and ranges from pale pink or tan in some patients, or can create white patches on the skin which is felt to be due to a chemical produced by the yeast that diffuses into the skin and inhibits normal skin pigmentation."
The pityriasis is often more noticeable when your skin is tanned, as the white patches contrast more from the colour of the rest of your skin.
"The yeast causing the problems is Malassezia - this can be found normally on healthy skin, but in some people it can grow more actively on the skin surface", Dr Borysiewicz continues. "We do not know why some people are more prone to this than others. It's not conventionally contagious as you need to be prone to the yeast build up. Your dermatologist will take a scraping from your skin for fungal culture to identify the yeast."
The dermatologist notes, "some people who are on tablets to lower their immune system such as steroids will be more prone to infection", and differs from other pigmentation conditions such as vitiligo as there is often a fine powdery scale on the surface of the skin.
The good news is, the condition is more of a nuisance than worrying.
"Once the yeast has been identified, patients will need treatment. This will depend on how widespread or symptomatic the rash is. For a small affected area an anti-yeast cream (Lamisil) will work. Or, for more widespread or stubborn areas, doctors will prescribe a short course of anti-yeast tablets (itraconazole for one week), along with an anti-yeast shampoo like Nizoral. Patients should use the shampoo as a body wash; this will need to be lathered onto the affected skin, left on for 10min, then rinsed off.
"Treatment will clear the infection and resolve the rash", the Catherine continued. "Although it is important to note that even pigmentation may not return for a number of months even after the scaling and rash have settled.
"Once patients have had one episode, it is possible to get further infections although the reason why some people's skin is more prone to infection is not completely understood. A way to reduce the frequency of recurrent infections is by using an anti-yeast shampoo such as Nizoral once a week as a body wash."
"There is a theory that Malassezia is more common in people who frequently moisturise their skin", Dr Borysiewicz adds. "So generally I tell patients to avoid over moisturising the areas of skin prone to the rash."
Dr Catherine Borysiewicz is a Consultant Dermatologist at the Cadogan Clinic.