White spots appear on your skin? Don't worry, it may not be vitiligo

Reviewer: Zhang Shuyuan, Chief Physician, Beijing Huayi Integrated Traditional Chinese and Western Medicine Dermatology Hospital

Many people worry about vitiligo when white spots appear on their skin. But when they go to the hospital for a checkup, they find out that they are not suffering from vitiligo but pityriasis versicolor.

Pityriasis versicolor is also a skin disease that can also cause a person's skin to turn white and cause white spots to appear. It can easily be mistaken for vitiligo. It can only be confirmed by finding the fungus through fungal microscopy.

1. What is the difference between pityriasis versicolor and vitiligo?

The white spots caused by pityriasis versicolor and the white spots caused by vitiligo look very similar on the surface, but there are actually differences between them.

Pityriasis versicolor, also known as tinea versicolor, is a superficial fungal disease caused by Malassezia infection of the epidermal stratum corneum. It is common on the chest, back, upper arms and armpits, and sometimes on the face. Patients with a long illness will have white macules on their skin, which will not disappear quickly even with the use of antifungal drugs, because these white spots are a type of hypopigmentation or depigmentation spots, which are caused by a special substance produced by Pityriasis versicolor that affects the pigment metabolism of the skin, resulting in the inhibition of melanin production.

Although pityriasis versicolor can be treated in the short term, it takes a long time for the pigment to recover. Without special treatment, the presence or absence of white spots in pityriasis versicolor depends on the degree and range of hypopigmentation or loss, and is also related to individual differences. Pityriasis versicolor patients are found all over the world, and are common in tropical and temperate regions with high relative humidity.

The white spots caused by pityriasis versicolor and those caused by vitiligo are different in their occurrence mechanism and skin lesion manifestations. The former is a decrease in pigmentation, while the latter is a complete disappearance of pigmentation.

Drugs for the treatment of vitiligo can promote the production of melanin in the skin and increase the amount of skin pigment. Of course, they can be used for the hypopigmented spots left over from pityriasis versicolor. If pityriasis versicolor has been cured and the remaining hypopigmented area is small and lighter in color, no treatment is required. Over time, most patients will recover on their own.

Vitiligo is a primary localized or generalized skin depigmentation disorder caused by local pigmentation disorder of the skin and decreased function of the tyrosinase system in the melanocytes of the skin and hair follicles, resulting in a significant lack of melanocytes in the epidermis, leading to skin depigmentation.

2. Symptoms, types and susceptible populations of pityriasis versicolor

The initial symptoms of pityriasis versicolor are dot-shaped macules surrounding the pores, which then gradually grow to the size of a nail plate with clear edges. Adjacent areas may merge into large irregular patches, with new macules appearing around them.

There are a small amount of easily peelable bran-like scales attached to the surface of the macules, which are gray, brown or yellow-brown in color. Sometimes multiple colors coexist and are shaped like spots. Macules that have been there for a long time will appear as light-colored spots.

The macules have no inflammatory reaction, but may cause mild itching. They are more common on the chest and back, but can also affect the neck, face, armpits, abdomen, shoulders, upper arms, etc. They are especially common in young and middle-aged men. The macules will decrease or disappear in winter, but may recur in summer.

Figure 1 Copyright image, no permission to reprint

There are four types of pityriasis versicolor:

Mottled type: initially it is light brown with a shiny surface, then the pigmentation fades, and due to the mixture of new and old lesions it becomes mottled.

Vitiligo type: After the skin removes scales or heals, the remaining pigmentation temporarily decreases.

Follicular type: Skin lesions are divided along the hair follicles, resembling follicular papules or plaques, with very thin scales.

Patchy type: There are fewer skin lesions, one or several patches, with thicker scales and darker color.

The following six types of people are susceptible to pityriasis versicolor:

People with a family history of the disease are at increased risk because there is a certain genetic susceptibility to the disease.

People who are often in hot and humid environments are prone to this disease.

It occurs frequently in the middle.

People with excessive oil secretion on the skin or prone to sweating.

People suffering from malnutrition and chronic diseases.

People who use glucocorticoids and immunosuppressants for a long time.

People who often wear non-breathable clothes.

3. The impact of pityriasis versicolor and how to prevent it

Although pityriasis versicolor can be cured, it still has many adverse effects on the patient's life.

If pityriasis versicolor is not treated in time, it will cause depigmentation or deposition, and it will cause itching when the lesions are active. In severe cases, cysts will form, affecting the image and even the patient's mental health and interpersonal relationships. In addition, pityriasis versicolor is contagious. If there is contact, it will also affect the health of family members and friends. In addition, the tinea versicolor fungus can affect the patient's lacrimal sac, causing the patient to suffer from obstructive dacryocystitis.

So how to prevent pityriasis versicolor?

The best way is to pay attention to skin hygiene, wipe it off in time after sweating; develop good personal hygiene habits, take a bath frequently, and remove sweat stains; the patient's underwear, bedding, sheets, pillows, etc. should be washed and dried or boiled to disinfect frequently; pay attention to nutrition, eat more fresh vegetables and fruits, eat less spicy food, and don't be picky about food.

Figure 2 Copyright image, no permission to reprint

Pityriasis versicolor is prone to recurrence and requires follow-up treatment after the rash has healed. It is best to use the medication for another half a month.

In short, if white spots appear on the skin, you should go to the hospital for diagnosis and treatment in time. Do not simply conclude whether you have vitiligo or pityriasis versicolor based on clinical manifestations. Treat under the guidance of a doctor.