What can cause white patches on the skin?

White patches on the skin can be caused by a variety of conditions, including vitiligo, pityriasis alba, tinea versicolor, idiopathic guttate hypomelanosis, and post-inflammatory hypopigmentation. Though some causes are benign and not a cause for concern, others can be due to an infectious, inflammatory, or autoimmune condition. Dr. Sima Stein, a board-certified pediatrician in San Jose, CA sees children of all ages for evaluation of rashes and skin examinations. Below is a brief overview of common skin diagnoses which can present as white
patches.

Vitiligo
Vitiligo results from a loss of skin cells called melanocytes. These cells are responsible for producing skin pigment, thus in their absence, the skin becomes hypopigmented or entirely without pigment. The exact cause of vitiligo is unknown, however both genetic and autoimmune processes are proposed as contributing factors. A diagnosis of vitiligo can often be made in office by medical examination alone, though a special type of light called a Wood light or biopsy
of the area can be confirmatory. Treatment involved sun protection, topical creams, and narrowband UVB therapy.

Pityriasis Alba
Pityriasis alba is a common skin condition in children and adolescents. The condition is not contagious or hereditary, though does demonstrate a higher prevalence in children with a history of eczema or other allergic conditions. These spots are generally located on the face and upper trunk. They start as scaly oval or round pink patches before fading and becoming hypopigmented. Though the hypopigmentation can be worrisome, pityriasis alba is benign and self-limited with complete repigmentation in most individuals. Treatment involves sun protection, topical creams, and mild emollients.

Tinea Versicolor
Tinea versicolor is a benign skin infection caused by a yeast-like fungus called Malessezia furfur. This fungus is normally found on human skin, but in hot humid climates, or in conditions which impact immune function, such as oral steroid use, pregnancy, and diabetes, this fungus can overgrow and cause scaly hypopigmented or hyperpigmented patches on the neck, trunk,
and face. Diagnosis can be made in office with by clinical appearance, using a wood light, or taking a small skin sample to look at under a microscope. Treatment includes topical antifungal shampoos or oral antifungals in more severe or frequent cases.

Idiopathic Guttate Hypomelanosis
Despite its long name, idiopathic guttate hypomelanosis is a common, benign skin condition which presents as small round hypopigmented spots in areas of repeated sun exposure (face, arms, legs). The condition is most common after the age of 30, though can present in children and adolescents. These spots do not require treatment, however are often a cosmetic concern.
For prevention, sun avoidance, sunscreen, and sun-protective clothing such as long sleeves and hats are recommended. Sunscreen should be SPF 30+ and be reapplied every two hours and after swimming.\

Post-Inflammatory Hypopigmentation
Inflammatory skin conditions, such as eczema or psoriasis, and trauma to skin, such as burns from hot water, can result in temporary lightening of the skin. These changes are generally more common in individuals with darker skin tones and present as flat, non-scaly hypopigmented areas. In the majority of cases, the skin returns to its normal pigment over time but this process can take weeks to months. While healing, it is important to keep the well protected from the sun
with sun-protective clothing and sunscreen.
Schedule with Dr. Sima Stein today for further information and answers to your questions!