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Emergency Medicine > DERMATOLOGY
Pityriasis Alba
Article Last Updated: May 22, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 10  
Author: Dara A Kass, MD, Clinical Assistant Instructor, Department of Emergency Medicine, State University of New York Downstate Medical Center, Kings County Hospital
Dara A Kass is a member of the following medical societies: American College of Emergency Physicians, Emergency Medicine Residents Association, and Society for Academic Emergency Medicine
Coauthor(s):
Richard Sinert, DO, Associate Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, Research Director, State University of New York College of Medicine; Consulting Staff, Department of Emergency Medicine, Kings County Hospital Center;
Reza Keshavarz, MD, MPH, Clinical Assistant Professor, Departments of Pediatrics and Emergency Medicine, Mount Sinai School of Medicine; Director of Pediatric Emergency Medicine, Mount Sinai Hospital
Editors: David A Peak, MD, Assistant Residency Director of Harvard Affiliated Emergency Medicine Residency, Attending Physician, Massachusetts General Hospital; Consulting Staff, Department of Hyperbaric Medicine, Massachusetts Eye and Ear Infirmary; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Mark W Fourre, MD, Program Director, Department of Emergency Medicine, Maine Medical Center; Associate Clinical Professor, Department of Surgery, University of Vermont School of Medicine; John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center; Pamela L Dyne, MD, Associate Professor, Program Director, Department of Medicine, Division of Emergency Medicine, University of California at Los Angeles School of Medicine
Author and Editor Disclosure
Synonyms and related keywords:
extensive pityriasis alba, hypopigmented dermatitis, pityriasis alba
Background
Pityriasis alba is a common hypopigmented dermatitis that occurs primarily in preadolescent children. It is often an incidental finding made on clinical examination. This is a self-limited disorder that usually resolves by adulthood.
Frequency
United States
Pityriasis alba is relatively common, occurring in up to 5% of children, but the exact epidemiology has not been described.
Mortality/Morbidity
It is generally self-limited and asymptomatic disease. There is no mortality. Cosmetic appearance may be an issue in extensive disease.
Race
Pityriasis alba does not seem to be more prevalent in any race; however, it is more obvious in dark-skinned individuals.
Age
Pityriasis alba is most common in children aged 3-16 years. It occasionally may occur in adults.
History
- Lesions often occur on the face of school-aged children.
- They may be erythematous or pruritic in the beginning, evolving into scaly, hypopigmented macules. Patients may complain that lesions are more prominent in the summer, secondary to the surrounding hyperpigmentations associated with prolonged sun exposure.
Physical
- A flaky, hypopigmented, patchy dermatitis with fine scales involving the face and, at times, the neck and shoulders typically is found.
- There can be numerous (up to 20 or more) hypopigmented macules, which are ill defined and range in size from 1-4 cm.
- The lesions of pityriasis alba tend to have less well-defined borders than lesions seen in vitiligo, and they do not coalesce as seen in tinea versicolor.
- An association with atopy is believed to exist; therefore, some patients may have atopic dermatitis as well.
Causes
- No definitive etiologic agent has been described.
- Hypopigmentation may occur in other disorders, such as those caused by fungi (eg, tinea versicolor), previous inflammatory conditions (eg, postinflammatory hypopigmentation), idiopathic disorders (eg, vitiligo), or malignancy (mycosis fungoides), or it may occur secondary to medications such as retinoic acid, benzoyl peroxide, and topical steroids. Clinicians should rule out these other disorders when evaluating a patient who may have pityriasis alba.
Dermatitis, Atopic
Dermatitis, Contact
Psoriasis
Tinea
Other Problems to be Considered
Mycosis fungoides
Lab Studies
- A workup may be undertaken to exclude other causes of hypopigmentation.
- Potassium hydroxide stain of a skin scraping will be positive if the patient has tinea versicolor.
- Wood light examination will help in a patient who has vitiligo.
Procedures
- A biopsy of the lesions usually is not necessary and not indicated in the emergency department. Pathologic findings are nonspecific; however, findings may include a basal layer with irregular pigmentation, follicular plugging, edema between epithelial cells (ie, spongiosis), or atopy of the sebaceous glands.
Emergency Department Care
No specific management is indicated or necessary in the ED.
Consultations
- Consultation with a dermatologist usually is unnecessary. The patient's primary care provider typically provides follow-up care.
- Extensive pityriasis alba may warrant a referral to a dermatologist for possible pulsed ultraviolet A (PUVA) therapy.
Since the disease usually is self-limited and asymptomatic, medical therapy is often unnecessary. Pityriasis alba has no medical consequences, and the side effects of the medications may outweigh the cosmetic benefit of intervention. The most commonly used remedies (eg, emollients, topical steroids, PUVA) appear to have limited efficacy.
Emollients are used to reduce the scaling of the lesions, especially on the face.
Topical steroids may help with erythema and pruritus during the initial lesions and may accelerate repigmentation of existing lesions.
Psoralen plus ultraviolet light A photochemotherapy (PUVA) may be used to help with repigmentation in extensive cases, although the recurrence rate is high after treatment is stopped.
Drug Category: Corticosteroids, topical
These agents have anti-inflammatory properties and cause profound and varied metabolic effects. They modify the body's immune response to diverse stimuli.
| Drug Name | Hydrocortisone (Cortaid, Cortizone-10) |
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| Description | An adrenocorticosteroid derivative suitable for application to skin or external mucous membranes. Has mineralocorticoid and glucocorticoid effects, resulting in anti-inflammatory activity. |
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| Adult Dose | Apply sparingly to affected areas bid/qid |
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| Pediatric Dose | Administer as in adults |
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| Contraindications | Documented hypersensitivity; not for use as monotherapy in primary bacterial infections (eg, cellulitis, angular cheilitis, impetigo, erysipelas, and paronychia); not for use in rosacea, perioral dermatitis, or acne; not for use on face, groin, or axilla |
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| Interactions | None reported |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Prolonged use, applying over large surface areas, application of potent steroids, and occlusive dressings may increase systemic absorption of corticosteroids and may cause Cushing syndrome, reversible HPA axis suppression, hyperglycemia, and glycosuria |
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Further Outpatient Care
- Outpatient follow-up generally is provided by a primary care provider.
- Extensive or recalcitrant cases may need the care of a dermatologist.
Prognosis
- Depigmentation is not permanent.
- Pityriasis alba generally is self-limited, and the lesions typically resolve by adulthood.
- The duration of symptoms is different for each patient. Parents should be aware lesions may persist for many months.
- Treatment may shorten the duration of the lesions to several weeks in certain cases.
Patient Education
- Education should focus on the lack of permanency of the dermatitis.
- Prolonged steroid therapy, especially on the face, is not necessary and may lead to toxicity.
- The lesions usually fade as the child grows older.
Medical/Legal Pitfalls
- Failure to address other causes of hypopigmentation such as vitiligo or tinea versicolor.
- Failure to diagnose mycosis fungoides in a patient with persistent lesions.
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- Hurwitz S. Clinical Pediatric Dermatology : A Textbook of Skin Disorders of Childhood and Adolescence. 2nd ed. Philadelphia: Saunders;1993: 60, 469-70.
- Lin RL, Janniger CK. Pityriasis alba. Cutis. Jul 2005;76(1):21-4. [Medline].
- Ortonne JP, Passeron T. Melanin pigmentary disorders: treatment update. Dermatol Clin. Apr 2005;23(2):209-26. [Medline].
- Rakel RE, Bope ET. Conn's Current Therapy 2005. 57th ed. St Louis: WB Saunders;2005: 999.
- Sams WM. Principles and Practice of Dermatology. New York: Churchill;1990: 369.
- Vargas-Ocampo F. Pityriasis alba: a histologic study. Int J Dermatol. Dec 1993;32(12):870-3. [Medline].
Pityriasis Alba excerpt Article Last Updated: May 22, 2006
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