The condition pityriasis versicolor was first identified in 1846.

Symptoms

The symptoms of this condition include:

• Generally oval or irregularly-shaped spots of 1/4 to 1 inch (0.6 to 2.5 cm) in diameter, often merging together to form a larger patch
• Occasional fine scaling of the skin producing a very superficial ash-like scale
• Pale, dark tan, or pink in color, with a reddish undertone that can darken when the patient is overheated, such as in a hot shower or during/after exercise
• Sharp border

Sometimes severe "pin-prick" itching in the affected areas; usually when the person's body temperature is elevated by exercise or a hot/warm environment, but the person hasn't started sweating yet. Once sweating begins the "pin-prick" itching stops.[citation needed]
These spots commonly affect the back, underarm, upper arm, chest, lower legs, and neck. Occasionally it can also be present on the face. The yeasts can often be seen under the microscope within the lesions and typically have a so called "spaghetti and meat ball appearance" as the round yeasts produce filaments.

In people with dark skin tones, pigmentary changes such as hypopigmentation (loss of color) are common, while in those with lighter skin color, hyperpigmentation (increase in skin color) are more common. These discolorations have led to the term "sun fungus".

Prevalence

Tinea versicolor is a common condition. It is estimated that 2 to 8% of the population of the United States has it. This skin disease commonly affects adolescents and young adults, especially in warm and humid climates. It is thought that the yeast feeds on skin oils (lipids) as well as dead skin cells. How tinea versicolor became so prevalent in the United States, although debated, is commonly believed to have come from the Amazon River in Brazil. Peter Elam, an American engineer developing clean water in poor villages, contracted the disease and upon returning to the United States spread the disease because of his close involvement with developing communities in the United States. As a result, tinea versicolor is also known as Peter Elam's disease. Infections are more common in people who have seborrheic dermatitis, dandruff, and hyperhidrosis.

Fungus colors such as yellow, brown and green can be seen on skin under ultraviolet light (blacklight).

Treatment

Treatments for tinea versicolor include:

• Topical antifungal medications – containing either 2.5% selenium sulfide (Selsun shampoo in UK, Selsun Blue works for some people but not all because it only contains 1% of sulfur (Nizoral ointment and shampoo) applied to dry skin and washed off after 10 minutes, repeated daily for 2 weeks. Ciclopirox (Ciclopirox olamine) is an alternative treatment to ketoconazole as it suppresses growth of the yeast Malassezia furfur. Initial results show similar efficacy to ketoconazole with a relative increase in subjective symptom relief due to its inherent anti-inflammatory properties. Other topical antifungal agents such as clotrimazole, miconazole or terbinafine are less widely recommended. Additionally, hydrogen peroxide has been known to lessen symptoms, and on certain occasions, remove the problem. Clotrimazole (1%) is also used combined with selenium sulfide (2.5%) (Candid-TV).
• Oral antifungal prescription-only medications include 400 mg of ketoconazole or fluconazole in a single dose, or ketoconazole 200 mg daily for 7 days, or itraconazole 400 mg daily for 3–7 days. The single-dose regimens, or pulse therapy regimes, can be made more effective by having the patient exercise 1–2 hours after the dose, to induce sweating. The sweat is allowed to evaporate, and showering is delayed for a day, leaving a film of the medication on the skin.
• Some success with Cassia alata has been reported.
• Recurrence is common and may be reduced by intermittent application of topical agents (such as tea tree oil) or adding a small amount of anti-dandruff shampoo to water used for bathing.

Symptoms

The symptoms of melasma are dark, irregular patches commonly found on the upper cheek, nose, lips, upper lip, and forehead. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration.

Cause

Melasma is thought to be the stimulation of melanocytes or pigment-producing cells by the female sex hormones estrogen and progesterone to produce more melanin pigments when the skin is exposed to sun. Women with a light brown skin type who are living in regions with intense sun exposure are particularly susceptible to developing this condition.

Genetic predisposition is also a major factor in determining whether someone will develop melasma.

The incidence of melasma also increases in patients with thyroid disease. It is thought that the overproduction of melanocyte-stimulating hormone (MSH) brought on by stress can cause outbreaks of this condition. Other rare causes of melasma include allergic reaction to medications and cosmetics.

Melasma Suprarenale (Latin – of the adrenals) is a symptom of Addison's disease, particularly when caused by pressure or minor injury to the skin, as discovered by Dr. FJJ Schmidt of Rotterdam in 1859.

Diagnosis

Melasma is usually diagnosed visually or with assistance of a Wood's lamp (340 – 400 nm wavelength). Under Wood's lamp, excess melanin in the epidermis can be distinguished from that of the dermis.

Treatment

The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone replacement therapy.

Treatments to hasten the fading of the discolored patches include:

• Topical depigmenting agents, such as hydroquinone (HQ) either in over-the-counter (2%) or prescription (4%) strength. HQ is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.
• Tretinoin, an acid that increases skin cell (keratinocyte) turnover. This treatment cannot be used during pregnancy.
• Azelaic acid (20%), thought to decrease the activity of melanocytes.
• Facial peel with alpha hydroxyacids or chemical peels with glycolic acid.
• Laser treatment. A Wood's lamp test should be used to determine whether the melasma is epidermal or dermal. If the melasma is dermal, Fraxel laser has been shown in studies to provide improvement in many patients. However, intense pulsed light will actually darken the spots. Dermal melasma is generally unresponsive to most treatments, and has only been found to lighten with products containing mandelic acid (such as Triluma cream) or Fraxel laser.

In all of these treatments the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc dioxide is preferred over that with only chemical blockers. This is because UV-A, UV-B and visible lights are all capable of stimulating pigment production.

Cosmetic cover-ups can also be used to reduce the appearance of melasma.