From the Guidelines
Pityriasis refers to a group of skin conditions characterized by fine scaling of the skin, with various types including pityriasis rosea, pityriasis alba, pityriasis versicolor, and pityriasis rubra pilaris, each with distinct characteristics, causes, and treatments. The term pityriasis originates from the Greek word "pityron" meaning bran, which describes the appearance of the skin flakes 1. Some common types of pityriasis include:
- Pityriasis rosea, a temporary rash with salmon-colored patches
- Pityriasis alba, characterized by light patches typically on children's faces
- Pityriasis versicolor, also known as tinea versicolor, a fungal infection causing discolored patches
- Pityriasis rubra pilaris, a rare inflammatory condition with reddish-orange scaly patches, which can resemble other forms of erythroderma, including atopic dermatitis, contact dermatitis, seborrheic dermatitis, cutaneous T-cell lymphoma, and psoriasis 1. Each type of pityriasis has different causes and treatments, such as pityriasis rosea typically resolving on its own within 6-8 weeks, while pityriasis versicolor requires antifungal medications 1. Proper diagnosis by a dermatologist is crucial as treatments vary significantly depending on the specific type of pityriasis 1.
From the Research
Definition of Pityriasis
- Pityriasis refers to a group of skin conditions characterized by scaling of the skin 2
- The term pityriasis was first used in print in 1684, according to the Merriam-Webster dictionary 2
Types of Pityriasis
- Pityriasis rosea: a common acute, self-limited papulosquamous dermatosis that primarily affects children and young adults 3
- Pityriasis versicolor: a superficial fungal infection of the stratum corneum caused by Malassezia species 4, 5
- Pityriasis rotunda: a rare disease characterized by round or oval patches, localized mainly on the trunk, arms, and legs 6
- Seborrheic dermatitis: a condition characterized by red scaly lesions predominantly located on the scalp, face, and upper trunk, which may be related to Malassezia 5
Characteristics of Pityriasis
- Scaling of the skin is a common feature of all pityriasis conditions 2
- Pityriasis rosea is characterized by a "herald patch" followed by oval erythematous squamous lesions along Langer's lines of cleavage on the trunk and proximal extremities 3
- Pityriasis versicolor is diagnosed clinically by its classic appearance of round or oval macules with fine scale that may be hyperpigmented or hypopigmented 4