Lota, the common name for the skin condition doctors call pityriasis versicolor (or tinea versicolor), is caused by an overgrowth of a yeast called Malassezia that naturally lives on your skin. This yeast is present on roughly 60% of healthy people without causing any problems. It only becomes visible as discolored patches when something triggers it to multiply beyond its normal levels.
The Yeast Behind Lota
Malassezia is a group of lipophilic (fat-loving) yeasts that make up part of the normal skin microflora on humans and other warm-blooded animals. At least seven species exist, and the most common one found on healthy skin is Malassezia globosa, accounting for about 42% of species identified in studies. Other species like M. sympodialis, M. furfur, and M. restricta round out the rest.
On healthy skin, these yeasts exist in a dormant round form and cause no harm. The trouble starts when conditions on the skin change and the yeast shifts into an active, rapidly growing form. As it multiplies, it produces enzymes that break down fatty acids in your skin’s natural oils. One of the byproducts of this process is azelaic acid, a compound that directly interferes with melanocytes, the cells responsible for producing your skin’s pigment. This chemical interference is what creates the characteristic lighter or darker patches of lota.
Why the Yeast Overgrows
Several factors can tip the balance from harmless colonization to visible infection:
- Hot, humid weather: Warmth and moisture create an ideal breeding ground for Malassezia, which is why lota is far more common in tropical and subtropical climates.
- Oily skin: The yeast feeds on skin oils (sebum), so people who produce more sebum are more susceptible. This also explains why lota tends to appear on the oiliest parts of the body.
- Heavy sweating: Excessive perspiration raises moisture levels on the skin surface and can trap the yeast against the skin, encouraging growth.
- Hormonal changes: Shifts in hormone levels, including those during puberty and pregnancy, can alter sebum production and make overgrowth more likely.
A weakened immune system can also play a role, though lota is overwhelmingly a condition that affects otherwise healthy people.
What Lota Looks Like
The patches of lota most commonly appear on the shoulders, back, upper chest, and sometimes the face and abdomen. What makes this condition distinctive is that the patches can look very different depending on your natural skin tone. On darker skin, lota typically shows up as white or light tan spots. On lighter skin, the patches tend to appear pink, light red, or slightly brown. The spots can also be yellow or tan on medium-toned skin.
The patches are usually flat and may have a fine, slightly scaly texture you can feel when you run your fingers over them. They often become more noticeable after sun exposure because the affected skin does not tan normally. Many people first realize they have lota during summer months when the contrast between the patches and surrounding skin becomes obvious. The spots may also merge together over time, forming larger irregular areas of discolored skin.
How Lota Is Diagnosed
A doctor can often identify lota just by looking at it, but a few simple tests confirm the diagnosis. One of the quickest is a Wood’s lamp examination, where a handheld ultraviolet light is held over the skin in a darkened room. Lota patches emit a distinctive orange glow under this light, which helps distinguish it from other skin conditions that may look similar.
Another common method involves gently scraping a small sample of skin from a patch and examining it under a microscope after applying a chemical solution. This reveals the characteristic “spaghetti and meatballs” appearance of Malassezia, a mix of round yeast cells and short filaments that confirm the fungal overgrowth.
Treatment Options
Most cases of lota respond well to topical antifungal treatments applied directly to the skin. Antifungal creams are typically applied once daily to the affected areas. Medicated shampoos containing antifungal agents can also be used as a body wash, lathered onto affected areas and left on for several minutes before rinsing. For mild or localized patches, topical treatment alone is usually enough to clear the infection within a few weeks.
For widespread or stubborn cases that don’t respond to topical products, oral antifungal medications are an option. These work from the inside out and can clear large areas more efficiently. Treatment courses vary, with some regimens lasting one to two weeks and others involving a single higher dose. Your doctor will determine the best approach based on how extensive the patches are.
Why the Patches Don’t Disappear Right Away
One of the most frustrating things about lota is that even after the yeast is successfully eliminated, the discolored patches persist for weeks to months. This is because the pigment damage has already been done. Your melanocytes need time to resume normal pigment production and gradually restore even color to the affected areas.
In clinical observations, skin typically begins showing restored integrity within three to four weeks of starting treatment. However, full repigmentation, where the patches blend back in with your surrounding skin tone, often takes considerably longer. Sun exposure on treated areas can help stimulate melanocyte activity and speed repigmentation, though you should use sunscreen to protect the rest of your skin. The key point: if your patches remain lighter or darker for a while after treatment, it does not mean the infection is still active.
Why Lota Keeps Coming Back
Recurrence is one of the hallmarks of lota. Because Malassezia is a permanent resident of your skin, you cannot eliminate it entirely. The same conditions that triggered the first episode, heat, humidity, oily skin, sweating, can trigger it again.
To reduce the chance of recurrence, many dermatologists recommend periodic use of antifungal washes even after the visible patches have cleared. Using a medicated shampoo as a body wash once or twice a month, particularly before the start of hot, humid seasons, can help keep the yeast population in check. Wearing breathable fabrics, showering promptly after heavy sweating, and avoiding excessively oily skin products also help minimize the conditions that allow Malassezia to flourish. People with a family history of fungal skin infections tend to have higher recurrence rates and may benefit from more consistent preventive care.