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Related to pityriasis rosea: pityriasis versicolor
Pityriasis rosea is a mild, noncontagious skin disorder common among children and young adults, and characterized by a single round spot on the body, followed later by a rash of colored spots on the body and upper arms.
Pityriasis rosea is most common in young adults, and appears up to 50% more often in women. Its cause is unknown; however, some scientists believe that the rash is an immune response to some type of infection in the body.
Causes and symptoms
Doctors do not think that pityriasis rosea is contagious, but the cause is unknown. Some experts suspect the rash, which is most common in spring and fall, may be triggered by a virus, but no infectious agent has ever been found.
It is not sexually transmitted, and does not appear to be contagious from one person to the next.
Sometimes, before the symptoms appear, people experience preliminary sensations including fever, malaise, sore throat, or headache. Symptoms begin with a single, large round spot called a "herald patch" on the body, followed days or weeks later by slightly raised, scaly-edged round or oval pink-copper colored spots on the trunk and upper arms. The spots, which have a wrinkled center and a sharp border, sometimes resemble a Christmas tree. They may be mild to severely itchy, and they can spread to other parts of the body.
A physician can diagnose the condition with blood tests, skin scrapings, or a biopsy of the lesion.
The rash usually clears up on its own, although a physician should rule out other conditions that may cause a similar rash (such as syphilis).
Treatment includes external and internal medications for itching and inflammation. Mild inflammation and itching can be relieved with antihistamine drugs or calamine lotion, zinc oxide, or other mild lubricants or anti-itching creams. Gentle, soothing strokes should be used to apply the ointments, since vigorous rubbing may cause the lesions to spread. More severe itching and inflammation is treated with topical steroids. Moderate exposure to sun or ultraviolet light may help heal the lesions, but patients should avoid being sunburned.
Soap makes the rash more uncomfortable; patients should bathe or shower with plain lukewarm water, and apply a thin coating of bath oil to freshly-dried skin afterwards.
Antihistamines — A group of drugs that block the effects of histamine, a chemical released during an allergic reaction.
Steroids — A group of drugs that includes the corticosteroids, similar to hormones produced by the adrenal glands, and used to relieve inflammation and itching.
These spots, which may be itchy, last for 3-12 weeks. Symptoms rarely recur.
American Academy of Dermatology. 930 N. Meacham Road, P.O. Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. Fax: (847) 330-0050. http://www.aad.org.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
any of various skin diseases characterized by the formation of fine, branny scales.
acute lichenoid pityriasis an acute or subacute, sometimes relapsing, widespread macular, papular, or vesicular eruption that tends to crusting, necrosis, and hemorrhage; when it heals it leaves pigmented depressed scars, followed by a new crop of lesions. Progression to the chronic lichenoid form occasionally occurs.
pityriasis al´ba a chronic condition with patchy scaling and hypopigmentation of the skin of the face.
chronic lichenoid pityriasis a chronic brown to red-brown scaly macular eruption, seen mainly on the trunk, with epidermal changes and a perivascular lymphocytic infiltrate. It may arise independently or happen as a progression of the acute lichenoid form.
pityriasis ro´sea a common acute or subacute, self-limited exanthematous disease of unknown etiology. It begins with a solitary red to tan plaque (herald plaque), usually on the trunk, arms, or thighs, which is followed by similar but smaller papular or macular lesions; these later may peel and leave a scaly collarette.
pityriasis ru´bra pila´ris a chronic inflammatory skin disease marked by pink scaling macules and cone-shaped horny follicular papules; it usually begins with severe seborrhea of the scalp and face, associated with keratoderma of palms and soles.
pityriasis versi´color tinea versicolor.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
pit·y·ri·a·sis ro·'se·aAvoid the mispronunciation rose'a.
A self-limited eruption of macules or papules involving the trunk and, less frequently, extremities, scalp, and face; the lesions are usually oval and follow the crease lines of the skin; occurs most commonly in children and young adults and is frequently preceded by a single larger scaling lesion known as the herald patch.
Farlex Partner Medical Dictionary © Farlex 2012
pityriasis roseaDermatology A skin condition, most common in young adults, with a 3:2 ♀:♂ ratio, seen in the fall and spring, lasting 4 to 8 wks, manifest as a single larger patch called a herald patch followed several days later by more rash. See GLC7.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
pi·tyr·i·a·sis ro·se·a(piti-rīă-sis rō-zēă)
A self-limited eruption of macules or papules involving the trunk and, less frequently, extremities, scalp, and face; the lesions are usually oval and follow the crease lines of the skin; the onset is frequently preceded by a single larger scaling lesion known as the herald patch.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
pityriasis roseaA common, mild skin disease, probably caused by a virus, and featuring flat, oval, reddish, scaly spots in the line of skin creases. A single prominent ‘herald’ patch usually occurs on the trunk or an arm about a week before the outbreak. The rash lasts for 6 to 8 weeks and then clears up without treatment. Itching may call for calamine lotion or antihistamine drugs.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
pi·tyr·i·a·sis ro·se·a(piti-rīă-sis rō-zēă)
A self-limited eruption of macules or papules involving the trunk and, less frequently, extremities, scalp, and face; the lesions are usually oval and follow the crease lines of the skin.
Medical Dictionary for the Dental Professions © Farlex 2012