This document discusses three skin conditions: Pityriasis versicolor, caused by fungi that cause flaky discolored patches, diagnosed using a wood lamp or microscopy; Pityriasis rosea, a self-limiting rash characterized by an oval herald patch and smaller scaly patches that resolves within 6-10 weeks, though the cause is unknown; and Pityriasis alba, a low-grade eczema seen in children that causes fine scaling and pale patches. Treatment focuses on relieving symptoms like itching with medicated creams, baths, or oral medications.

1. PITYRIASIS
Dr Javeria Khalid MBBS,RMP

3. PITYRIASIS VERSICOLOR
 Pityriasis versicolor is a common yeast infection of the skin, in which flaky
discolored patches (hypopigmented) appear on the chest and back.
 More frequent in hot and humid climates

5. CAUSES
 Pityriasis versicolor is caused by fungi Malassezia.
 Most common species
M globosa,
Less common
M restricta and M sympodialis.

6. DIAGNOSIS
 Wood lamp (black light) examination
 Microscopy of a skin scraping (using potassium hydroxide (KOH) to remove
skin cells) — hyphae and yeast cells that resemble spaghetti and meatballs
 Fungal culture — this is usually reported to be negative, as it is quite difficult to
persuade the yeasts to grow in a laboratory
 Skin biopsy — fungal elements may be seen within the outer cells of the skin
(stratum corneum) on histopathology. Special stains may be required.

8. TREATMENT
 Topical measures
Selenium sulfide shampoo
Topical antifungal
 Systemic measures
Oral Anti fungal
 Exercise

9. Pityriasis Rosea
 Pityriasis rosea is a self-limiting rash, which resolves in about 6–10 weeks. It is
characterised by a large circular or oval "herald patch", usually found on the chest,
abdomen, or back.
 The herald patch is followed some time later, typically two weeks or so, by the
development of smaller scaly oval red patches, resembling a Christmas tree,
distributed mainly on the chest and back.

10.  The herald patch is a single patch that appears before the generalised rash of
pityriasis rosea. It is a slightly raised, oval, salmon-pink or red plaque 2–5 cm in
diameter, with a peripheral scale trailing just inside the edge of the lesion, like a
collaret.

12. CAUSE
 The cause of pityriasis rosea is not known, but it is commonly believed to be
caused by a virus or bacteria

13. TREATMENT
 The goal of treatment for pityriasis rosea is to relieve symptoms associated with the
condition, such as itching.
Treatment may include:
 Medicated lotions and creams (to soothe the itching)
 Medicines by mouth (to ease the itching)
 Cool baths with or without oatmeal (to soothe the itching)
 Ultraviolet exposure (under a healthcare provider's supervision)
 Cool compresses (to soothe the affected skin)
There is no cure for pityriasis rosea. The condition will usually resolve on its own in
about 1 to 3 months. Normally, it does not return.

14. Pityriasis alba
 Pityriasis alba is a low-grade type of eczema/dermatitis mainly seen in children.
 The name describes its appearance: pityriasis refers to the characteristic fine scale,
and alba to its pale colour (hypopigmentation).
 Pityriasis alba is common worldwide with a prevalence in children of around 5%.
 The hypopigmentation of pityriasis alba is more prominent, and the condition
perhaps more common, in dark skin compared to white skin