This Daily Doodle illustrates Pityriasis Versicolor (aka tinea versicolor), a superficial cutaneous fungal infection that typically presents as numerous irregularly well demarcated macules of hypopigmented or hyperpigmented skin on the chest, back or proximal extremities. These macules can enlarge and merge together, forming extensive geographic areas.
Pityriasis Versicolor is caused by a type of yeast known as Malassezia furfur. These yeast (represented by the slices of bread in the doodle) are normally found on skin, however, in warm and humid climates they start to overgrow and misbehave. The changes in skin color is caused by dicarboxylic acids formed by enzymatic oxidation of fatty acids in lipids of the skin’s surface. This inhibits tyrosinase in the epidermal melanocytes thereby inhibiting melanin synthesis and resulting in variable pigmentation .
Rather than depicting M. furfur as slices of bread, I should have drawn them as clumps of spaghetti and meatballs. “Spaghetti and meatballs” is the term used to describe the filamentous hyphae and globose yeast forms under direct microscopic examination of scales prepared with KOH.
Malassezia infections are not contagious and they usually have no other symptoms other than the skin discoloration and sometimes mild pruritus (itchiness). Management typically involves selenium sulfide body lotion or topical agents such as azole creams (ketoconazole, econazole, micronazole, clotrimazole) .
- What is another name for Pityriasis Versicolor?
- How does it present clinically?
- What causes Pityriasis Versicolor?
- Is it contagious?
- What term is used to describe its appearance under direct microscopic examination?
- How is Pityriasis Versicolor treated?
- K. Wolff and R. Johnson. “Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology”. 6th Edition. 2009. McGraw Hill Publishing Company.
“Tinea Versicolor” Daily Doodle by Michiko Maruyama