Human skin is home to numerous microbes that are normally harmless to health, but which can begin to proliferate triggering dermatological problems.
Among these are the fungi responsible for pityriasis versicolor (also known as tinea versicolor, and in English Pityriasis versicolor), a non-contagious disease particularly frequent in hot and humid climates of tropical and subtropical countries and which can easily develop in case of oily skin, profuse sweating or weakening of the immune system.
Fortunately, this is not a dangerous disorder. However, the fungus, proliferating, can create patches on the skin that are not beautiful to show off, especially when they occupy large areas of the skin or converge forming larger patches.
Here are the main characteristics of pityriasis versicolor.
Affected areas | Shoulders, neck, upper arms, back, abdomen |
Features of lesions | Circular-ovoid patches of contrasting color with that of healthy skin (pink on tanned skin; coffee-milk on light skin) with a tendency to converge, forming larger asymmetrical “map” patches |
Symptoms | Usually asymptomatic; sometimes itching of varying intensity |
What is it
It is a benign skin infection, generally not contagious, due to the proliferation of yeasts (or fungi) normally present on the human epidermis, belonging to the genus Malassezia.
Specifically, it is Malassezia furfur, a saprophytic fungus (which proliferates by feeding on decomposing organic substances) more recently defined as Pityrosporum orbicolare.
The disease is not dangerous but it is a source of annoying blemishes. Women are generally particularly affected.
Causes
The disease occurs when, due to particular skin conditions, yeast manages to penetrate below the surface of the skin (i.e. the layer of the epidermis) and proliferate.
The non-contagiousness is due precisely to the fact that pityriasis develops not so much for the presence of yeast, but for the conditions of the skin.
It usually occurs in the hot months in conjunction with excessive sweating or sebaceous hypersecretion, and is also partly linked to the specific composition of these excretions, which varies from individual to individual.
To favor its appearance, however, can also be hormonal changes and an immune system weakened by:
- pregnancy;
- malnutrition;
- use of corticosteroids;
- diabetes;
- other disorders.
It is frequent among those who frequent very humid environments such as swimming pools.
Most common symptoms
The disease manifests itself with alterations in skin pigmentation, consisting of flat and irregularly shaped spots, darker or lighter in color than the surrounding skin.
As also happens in the case of another pityriasis (the amiantaceous one that affects the scalp), the spots, which occur most often on the arms, chest, abdomen and neck, tend to peel with a simple pressure of the nail, but only rarely give itching.
The manifestation, then, also varies according to age: in fact, in newborns and infants, the spots – light and roundish – are widespread mainly on the face.
Usually we realize that we suffer from it in the summer, when tanning highlights the most depigmented areas.
Other types of skin mycosis
There are other types of skin mycoses, which differ from pityriasis versicolor depending on the affected areas of the body, the characteristics of the lesions and the symptoms.
Mycosis | Affected areas | Features of lesions | Symptoms |
---|---|---|---|
Tinea corporis | Face, neck, trunk, arms and legs, in hairless areas | Circular patches, with raised edge, reddened and peeling, vaults with vesicles, and lighter and smoother central part, which progressively enlarge | Usually asymptomatic; sometimes mild burning or itching |
Tinea cruris | Skin folds, especially inguinal folds | Large annular patches, with raised edge, reddened and flaky, which progressively widen | Often associated with itching; sometimes mild burning |
Tinea pedis | Space between the toes, especially between the 4th-5th toes | Soft, yellowish-white, macerated, slightly skinned scaly and with slight redness. If severe and infected, they are present more intense redness, swelling, fissures and erosions exuding | Almost always associated with itching; often burning and discomfort |
Onychomycosis | Toenails and fingernails | Alterations of different parts of the nail, which becomes whitish-yellowish, soft, brittle, with a tendency to crumble and/or lifting from the nail bed | Usually asymptomatic; sometimes mild burning or pain if the supporting tissues of the nail become inflamed |
Cutaneous candidiasis | Skin folds of various parts of the body (submammary, inguinal, abdominal in obese people) and spaces between fingers | Bright red spots, sometimes eroded and shiny covered with a patina whitish powdery or with whitish border macerated at the edges. Can vesicles or pustules may also be present near the patch main. Tend to be scaly | Always associated with itching; often mild swelling, burning or pain |
Treatment
Sometimes the problem seems to solve itself… but only in appearance! Pityriasis, in fact, does not heal if left untreated. The spots can disappear when temperatures drop, only to return with the summer, when the air warms up again and the climate becomes more humid.
To effectively combat the problem, however, specific treatments are necessary. The choice of the most suitable approach depends on several factors, including the affected area of the body, the extent of the problem and the thickness of the spots.
In general, the types of treatment that help to get the better of pityriasis versicolor are two. The most common is the topical one, which involves the local application of ointments or lotions based on antifungals such as bifonazole, clotrimazole, fluconazole or other antifungal substances.
To prevent relapses it is also useful to use soaps or detergents with antifungal action, both during therapy and in the hottest periods of the year.
It is in fact quite easy for the disorder to recur because the fungus is a habitual guest of the skin and the hair follicles can act as a reservoir of the microorganism.
When, on the other hand, the problem is particularly extensive, the patches are thick or relapses are frequent, it is possible that oral medicines may have to be taken. However, only a doctor can prescribe such treatment.
To learn more about these drugs read the Antifungal tab.
Effective treatments
Treatment is generally effective. However, the skin can remain stained for a few weeks or a few months. In addition, tanning can make any spots more evident. For this reason, once the treatment is finished, it is important to protect the skin with an adequate sunscreen.
However, we should not be surprised if the problem recurs. In fact, if there is a personal predisposition or the presence of some risk factors such as a hot-humid climate, the fungus can resume proliferating without control.
To prevent recurrence, it is possible to rely on medicated detergents, i.e. products that help to avoid the proliferation of the microbe. Among the most used are, for example, selenium sulfide shampoo and topical azoles (such as ketoconazole) and, for everyday cleansing, zinc pyrithione orsalicylic sulpharate-based soaps. They can be used once or twice a month – especially during hot and humid periods of the year – by those who have already dealt with pityriasis versicolor to prevent its reappearance.
When to consult your doctor
In the presence of spots on the skin, to make sure that it is not vitiligo, another skin disease or a fungal infection of different origin, it is advisable to consult a doctor and / or undergo a dermatological examination.
The doctor formulates the diagnosis based on the typical symptoms of this skin disorder. To confirm this, it takes (“scraping” it from the skin) a sample which, mixed with a fresh preparation with potassium hydroxide, is observed under a microscope in search of hyphae (ie the filaments that make up the body of fungi) and budding cells.
In case of doubt, then, the specialist can observe the spots on Wood’s lamp, an instrument under whose light the pityriasis spots show a characteristic luminescence (a clear golden fluorescence).
Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.
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