| Patient Education |
|
Click here for patient education.
|
|
You are in: eMedicine Specialties >
Pediatrics: General Medicine > Dermatology
Pityriasis Alba
Article Last Updated: Nov 30, 2007
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Mark A Crowe, MD, Assistant Clinical Instructor, Department of Medicine, Division of Dermatology, University of Washington School of Medicine
Mark A Crowe is a member of the following medical societies: American Academy of Dermatology and North American Clinical Dermatologic Society
Editors: Kevin P Connelly, DO, Clinical Assistant Professor, Department of Pediatrics, Division of General Pediatrics and Emergency Care, Virginia Commonwealth University; Medical Director, Paws for Health Pet Visitation Program; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Robert A Schwartz, MD, MPH, Professor and Head of Dermatology, Professor of Medicine, Professor of Pediatrics, Professor of Pathology, Professor of Preventive Medicine and Community Health, UMDNJ-New Jersey Medical School; Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences; William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System
Author and Editor Disclosure
Synonyms and related keywords:
pityriasis alba, PA, erythema streptogenes, furfuraceous impetigo, pityriasis sicca faciei, pityriasis simplex, pityriasis streptogenes, pityriasis alba, skin disorder, xerosis, atopic diathesis, hyperkeratosis, parakeratosis, hypopigmentation, atopic dermatitis, eczema, cheilitis, Dennie-Morgan infraorbital fold, wool intolerance, infra-auricular fissuring, contact dermatitis, tinea versicolor, vitiligo, nevus depigmentosus, psoriasis, tinea faciei, tinea corporis
Background
Pityriasis alba (PA) is a relatively common skin disorder in children and young adults. It is characterized by the presence of ill-defined, scaly, faintly erythematous patches that subside to leave areas of hypopigmentation. Lesions may progress through the following 3 clinical stages:
- Papular (scaling) erythematous
- Papular (scaling) hypochromic
- Smooth hypochromic
Lesions eventually subside, leaving areas of hypopigmentation that slowly repigment to normal. The duration of PA varies from one month to 10 years, but most cases resolve over several months to one year. Diagnosis is made clinically, and treatment consists of skin care and education of the parents about the benign nature of the disorder. Hydrocortisone may decrease erythema, scale, and pruritus, if present. PA is a nonspecific finding that is commonly associated with atopic dermatitis. Xerosis that presents in individuals with atopic diathesis is an important element in the development of the disease. The etiology is unknown.
Pathophysiology
In a study of 9 patients with extensive PA, the density of functional melanocytes was reduced in the affected areas without any change in cytoplasmic activity.1 The melanosomes tended to be fewer and smaller, but their distribution pattern in the keratinocytes was normal. Melanosomal transfer to keratinocytes was generally not disturbed. Histology was nonspecific. Hyperkeratosis and parakeratosis were not consistently present, and they are seemingly unlikely to play a significant role in the pathogenesis of the hypomelanosis. A variable degree of intercellular edema and intracytoplasmic lipid droplets were present. Hypopigmentation may be primarily due to the reduced numbers of active melanocytes and a decrease in number and size of melanosomes in the affected skin.
Frequency
United States
Although the exact incidence has not been described, up to one third of school-aged children may have this disorder. PA is not seasonal, but the dry slightly scaling appearance tends to worsen during cold months, when the air is relatively dry inside the home. In addition, sun exposure may make the lesions more obvious during spring and summer. The condition is more common in patients with a history of atopy.
International
In a large study of 9955 schoolchildren aged 6-16 years who lived in a tropical region, the prevalence of PA was 9.9%.2
Mortality/Morbidity
- PA is generally self-limited and asymptomatic.
- Cosmetic appearance may be an issue in some patients.
- Daycare facilities and schools may voice concern about the disorder and request the child be evaluated to rule out an infectious disease.
Race
- PA occurs in people of all races.
- One study found the incidence to be slightly higher in light-skinned people.
- The condition is frequently more apparent and cosmetically bothersome in patients with darker complexions.
Sex
PA is more prevalent in males than in females.
Age
- PA is most common in children aged 3-16 years. Ninety percent of cases occur in children younger than 12 years.
- PA occasionally occurs in adults.
History
- Pityriasis alba (PA) is generally asymptomatic, but it may be mildly pruritic.
- Patients may describe any of the following 3 clinical stages:
- Papular erythematous lesions
- Papular hypochromic lesions
- Smooth hypochromic lesions
- Initially, erythema may be conspicuous, and minimal serous crusting of some lesions may occur; however, because the erythema is usually very mild, most parents do not recall the erythematous stage.
- Recurrent crops of new lesions may develop at intervals.
- The duration of PA varies from one month to 10 years. The average duration of the common facial form in childhood is one year or more.
- Important aspects of patient history include the following:
- Patient or family history may include asthma, hay fever, or eczema in the characteristic areas of atopic dermatitis. PA is a nonspecific finding that is commonly associated with atopic dermatitis.
- The patient may have prior history of rash or eczema at the sites of hypopigmentation; skin irritation produced by any of various causes may heal with postinflammatory hypopigmentation.
- Ask about prior therapy; potent topical steroids may produce hypopigmentation. Patients may develop irritant or allergic contact dermatitis to various topical creams, lotions, and medications. When these are discontinued and the area recovers from the contact dermatitis, an area of postinflammatory hypopigmentation may occur.
- Look for seasonal variations in appearance; the scaling areas of hypopigmentation frequently develop during winter but become more apparent following sun exposure during the spring and summer.
Physical
- Characteristic lesions
- PA is characterized by hypopigmented, round-to-oval, scaling patches on the face, upper arms, neck, or shoulders. The legs and trunk are less commonly involved.
- Lesions vary in size, usually 1-4 cm in diameter.
- Most commonly, patients have multiple lesions that range in number from 4 or 5 to 20 or more.
- Scales are fine and adherent.
- Affected areas
- In approximately one half of all patients, the lesions are limited to the face. In children, the lesions are often confined to the face. The areas around the mouth, chin, and cheeks are the most commonly affected.
- In 20% of affected children, the neck, arms, and shoulders are involved in addition to the face.
- Less commonly, the face is spared and scattered lesions are present on the trunk and limbs.
- Rarely, the disease may be quite extensive. Patients with extensive PA present with numerous lesions on the trunk and extremities. This form of PA generally occurs in older patients, and the lesions may be more persistent.
- Important aspects of examination
- Examine patients for keratotic lesions on the elbows and knees and for small pits in the nails, which may suggest a diagnosis of psoriasis.
- Examine for the following potential signs of atopic dermatitis:
- Eczema in the popliteal or antecubital fossa
- Nipple eczema
- Cheilitis
- Dennie-Morgan infraorbital fold
- Anterior neck folds
- Wool intolerance
- White dermographism
- Infra-auricular fissuring
Causes
- No definitive etiologic agent has been described.
- Excessively dry skin, which is frequently exacerbated by cold dry environments, appears to be a common factor.
- Lesions are visible primarily in contrast to dark skin. Increasing sunlight in spring and summer makes them more apparent.
- The condition is not contagious, and no infectious agent has been identified.
Atopic Dermatitis
Contact Dermatitis
Pityriasis Rosea
Tinea Versicolor
Other Problems to be Considered
Hypopigmented mycosis fungoides
Nevus depigmentosus
Nummular eczema
Pigmenting pityriasis alba (PA)
Progressive and extensive hypomelanosis
Progressive macular hypomelanosis
Psoriasis
Seborrhea
Tinea corporis
Vitiligo Hypopigmentation Any inflammatory process that involves the skin, such as contact dermatitis, can leave areas of hypopigmentation upon healing. This may occur in other disorders, including those caused by fungi (eg, tinea versicolor), previous inflammatory conditions (ie, postinflammatory hypopigmentation), or idiopathic disorders (eg, vitiligo). Hypopigmentation may also result as a side effect of medications such as retinoic acid, benzoyl peroxide, and topical steroids. The most common disorders of hypopigmentation in children are PA, vitiligo, nevus depigmentosus, and tinea versicolor. Nevus depigmentosus The localized form of nevus depigmentosus must be distinguished from an ash leaf spot, the earliest cutaneous manifestation of tuberous sclerosis, whereas the systematized form may be confused with hypomelanosis of Ito, another neurocutaneous disorder. Nummular eczema Nummular eczema is intensely pruritic. Pigmenting PA This condition seems to be a variant of classic PA, showing a strong association with dermatophyte infection, especially tinea capitis. It may be related to lichenoid melanodermatitis. The characteristic morphology of pigmenting PA includes a central zone of bluish hyperpigmentation surrounded by a hypopigmented slightly scaly halo of variable width. Patients display lesions primarily on the face. Psoriasis In older children and adults, the early erythematous lesions of PA may be mistaken for psoriasis; however, the distribution, the lack of psoriatic scales, and the sparing of scalp, elbows, and knees exclude this diagnosis. Tinea versicolor The lesions of tinea versicolor favor the upper trunk of adolescents. Potassium hydroxide examination of the associated scale reveals hyphal and yeast forms of Malassezia furfur. Vitiligo Vitiligo is an acquired progressive disorder, in contrast to nevus depigmentosus, which is a stable congenital leukoderma. The face is a common site for vitiligo, but the distribution is most commonly around the eyes or mouth, and, in contrast to PA, the pigment loss is complete.
Lab Studies
- The correct diagnosis is usually suggested by the age of the patient, fine scaling, hypopigmentation, and the distribution of lesions.
- A potassium hydroxide (KOH) examination may be performed to rule out tinea versicolor, tinea faciei, or tinea corporis.
Histologic Findings
Skin biopsy is not usually necessary or particularly helpful in establishing the diagnosis. It may be indicated if the diagnosis of mycosis fungoides (cutaneous T-cell lymphoma) is a significant possibility. Only a few histologic studies have been reported, and most maintain that the microscopic features of pityriasis alba (PA) are those of a chronic nonspecific dermatitis. Histologic studies reveal features that are suggestive, although not pathognomonic, of the diagnosis. A histopathologic diagnosis of PA may be proposed when the following features are observed in a biopsy specimen taken from a skin lesion with follicular papules:
- Irregular pigmentation by melanin of the basal layer
- Follicular plugging
- Follicular spongiosis
- Atrophic sebaceous glands
On electron microscopy findings, numbers of active melanocytes are reduced and the number and size of melanosomes are decreased in affected skin.
Medical Care
- Treatment of pityriasis alba (PA) primarily consists of good general skin care and education of the parents about the benign nature of this self-limited disorder.
- Hydrocortisone or a bland emollient cream may decrease erythema, scale, and pruritus, if present. For chronic lesions on the trunk, a mild tar paste may be helpful.
- Patients should use adequate sun protection to prevent darkening of the natural skin color. Lesions of PA do not repigment well upon sun exposure, and darkening of the surrounding skin may worsen the cosmetic appearance.
Consultations
- Extensive PA may warrant a referral to a dermatologist for possible oral psoralen and UVA photochemotherapy (PUVA). PUVA for extensive PA may achieve a marked degree of improvement; however, PUVA is not without risks and is seldom required.
- Consultation with a dermatologist is usually unnecessary; the patient is typically monitored by the primary care provider.
Because the disease is usually self-limited and asymptomatic, medical therapy is not always necessary. Topical steroids, tacrolimus ointment 0.1%, and emollients are safe and usually effective treatment. Because of the high cost of tacrolimus, it is seldom indicated as therapy for PA.
Drug Category: Corticosteroids, topical
The low-strength class 5 or 6 topical steroids that may be used to treat pityriasis alba (PA) are extremely safe in young children. Prolonged use on the face is not recommended. Very potent topical steroids may be absorbed to a degree that may cause significant metabolic effects and impede normal growth rates. This is more likely in children younger than 2 years, in whom the application is to a relatively large percentage of the body surface area. Potent topical steroids may also produce atrophy of the skin and an acneform eruption. They should not be used on the face.
| Drug Name | Hydrocortisone, topical (Cortaid, Cortizone-10, Dermacort) |
|---|
| Description | This is an adrenocorticosteroid derivative with mild anti-inflammatory activity. Creams and ointments are generally well tolerated, but ointments may be more effective in patients with significant xerosis or scales. |
|---|
| Adult Dose | Apply sparingly to affected area bid/qid |
|---|
| Pediatric Dose | Apply as in adults |
|---|
| Contraindications | Documented hypersensitivity; viral, fungal, and bacterial skin infections |
|---|
| Interactions | None reported |
|---|
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Low-strength topical steroids are extremely safe in young children and do not cause hypothalamic-pituitary-adrenal (HPA) axis suppression, Cushing syndrome, hyperglycemia, or glycosuria; very potent topical steroids may be absorbed after prolonged use on large surface areas and may produce these significant side effects |
|---|
Drug Category: Immunosuppressant Agent
Tacrolimus ointment may be used to treat PA and is extremely safe in young children. However, because it is expensive, it is seldom indicated for the treatment of PA.
In 2005, the US Food and Drug Administration (FDA) issued a public health advisory to inform healthcare professionals and patients about a potential cancer risk from use of tacrolimus ointment. This concern is based on information from animal studies, case reports in a small number of patients, and knowledge of how drugs in this class work. It may take human studies of 10 years or longer to determine if use of tacrolimus ointment is linked to cancer. In the meantime, this risk is uncertain, and FDA advises tacrolimus ointment should be used only as labeled, for patients after other prescription treatments have failed to work or cannot be tolerated.
This information reflects FDA’s preliminary analysis of data concerning this drug. FDA is considering, but has not reached a final conclusion about, this information. FDA intends to update this sheet when additional information or analyses become available. For more information, see FDA MedWatch.
| Drug Name | Tacrolimus topical ointment (Protopic) |
|---|
| Description | The mechanism of action of tacrolimus in atopic dermatitis is not known. Reduces itching and inflammation by suppressing the release of cytokines from T cells. Also inhibits transcription for genes that encode IL-3, IL-4, IL-5, GM-CSF, and TNF-alpha, all of which are involved in the early stages of T-cell activation. Additionally, may inhibit release of pre-formed mediators from skin mast cells and basophils, and downregulate expression of FCeRI on Langerhans cells. Can be used in patients as young as 2 years old. Drugs of this class are more expensive than topical corticosteroids. It is available as an ointment in concentrations of 0.03 and 0.1%. Indicated only after other treatment options have failed. |
|---|
| Adult Dose | Apply thin layer (0.1% ointment) to affected skin areas bid and rub in gently and completely; continue treatment for 1 wk after clearing of signs and symptoms
Short-term and intermittent use only |
|---|
| Pediatric Dose | <2 years: Not established
2-15 years: Apply 0.03% ointment bid to affected area(s)
>15 years: Administer as adults
Short-term and intermittent use only
|
|---|
| Contraindications | Documented hypersensitivity to tacrolimus or components of ointment |
|---|
| Interactions | None reported |
|---|
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Patients may experience a burning sensation during first few days of application; skin can become photosensitive and patients should be cautioned about exposure to direct or artificial sunlight and to use sunscreen; safety and efficacy in infected atopic dermatitis is not known; application under occlusion, which may promote systemic exposure, has not been evaluated (do not use tacrolimus ointment with occlusive dressings); absorption of tacrolimus following topical applications of tacrolimus ointment is minimal (relative to systemic administration), but tacrolimus is excreted in human milk and, thus, a decision should be made whether to discontinue nursing or to discontinue drug, taking into account importance of drug to mother (potential for serious adverse reactions in nursing infants from tacrolimus should also be a concern); caution with conditions that suppress the immune system (eg, AIDS, cancer); possible risk of lymph node or skin cancer based on animal studies and a small number of patients; may increase risk of viral infections; other adverse effects include headache, sore throat, flulike symptoms, fever, and cough |
|---|
Further Outpatient Care
- Sun protection with hats, clothing, and appropriate sunscreens is always appropriate. It may help diminish the appearance of lesions by limiting the difference in skin color between normal and involved skin.
- A primary care provider generally performs outpatient follow-up, if it is required.
Complications
- Risk of sunburn is slightly increased in areas of hypopigmentation.
Prognosis
- Pityriasis alba (PA) is generally self-limited, and patients are asymptomatic. Cosmetic appearance may be an issue with some pediatric patients, but it is more likely to be an issue with their parents.
- Prognosis is good, with eventual complete repigmentation. No long-term residual effects are expected.
Patient Education
- Educate the parents about the benign self-limited nature of the disorder.
- Although a few weeks of therapy with topical steroids may decrease erythema and pruritus in some patients, prolonged steroid therapy is not recommended. Use only low-potency (class 5, 6) topical steroids.
- Patients should use adequate sun protection to prevent darkening of their natural skin color. Lesions of PA do not repigment well after sun exposure; darkening of the surrounding skin may worsen the cosmetic appearance.
Special Concerns
- Daycare facilities and schools may voice concern about the disorder and request the child be evaluated to rule out an infectious disease.
| Media file 1:
Note the characteristic, ill-defined, hypopigmented macules in this 6-year-old child with pityriasis alba. |
 |  View Full Size Image | |
Media type: Photo
|
| Media file 2:
Lesions of pityriasis alba are usually bilateral and located on the face, arms, and neck. |
 | View Full Size Image | |
Media type: Photo
|
| Media file 3:
The hypopigmentation produced by pityriasis alba may take a year or longer to return to normal. |
 | View Full Size Image | |
Media type: Photo
|
| Media file 4:
This older patient with areas of hypopigmentation on the face has a common problem that would be included in the differential diagnosis of pityriasis alba. Several months earlier, he had areas of irritant contact dermatitis on his cheeks. When those resolved, he was left with areas of postinflammatory hypopigmentation. These should eventually repigment to an even skin tone. |
 | View Full Size Image | |
Media type: Photo
|
- Zaynoun ST, Aftimos BG, Tenekjian KK, et al. Extensive pityriasis alba: a histological histochemical and ultrastructural study. Br J Dermatol. Jan 1983;108(1):83-90. [Medline].
- Bechelli LM, Haddad N, Pimenta WP, et al. Epidemiological survey of skin diseases in schoolchildren living in the Purus Valley (Acre State, Amazonia, Brazil). Dermatologica. 1981;163(1):78-93. [Medline].
- Blessmann Weber M, Sponchiado de Avila LG, Albaneze R, et al. Pityriasis alba: a study of pathogenic factors. J Eur Acad Dermatol Venereol. Sep 2002;16(5):463-8. [Medline].
- Di Lernia V, Ricci C. Progressive and extensive hypomelanosis and extensive pityriasis alba: same disease, different names?. J Eur Acad Dermatol Venereol. May 2005;19(3):370-2. [Medline].
- du Toit MJ, Jordaan HF. Pigmenting pityriasis alba. Pediatr Dermatol. Mar 1993;10(1):1-5. [Medline].
- Fink-Puches R, Chott A, Ardigo M, et al. The spectrum of cutaneous lymphomas in patients less than 20 years of age. Pediatr Dermatol. Sep-Oct 2004;21(5):525-33. [Medline].
- Fujita WH, McCormick CL, Parneix-Spake A. An exploratory study to evaluate the efficacy of pimecrolimus cream 1% for the treatment of pityriasis alba. Int J Dermatol. Jul 2007;46(7):700-5. [Medline].
- Hambly EM, Wilkinson DS. [Some atypical forms of eczema in children (author's transl)]. Ann Dermatol Venereol. Apr 1978;105(4):369-71. [Medline].
- Hurwitz S. Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhoodand Adolescence. 2nd ed. Philadelphia, PA: WB Saunders Co; 1993:469-70.
- Jorizzo J, Levy M, Lucky A, et al. Multicenter trial for long-term safety and efficacy comparison of 0.05% desonide and 1% hydrocortisone ointments in the treatment of atopic dermatitis in pediatric patients. J Am Acad Dermatol. Jul 1995;33(1):74-7. [Medline].
- Lin RL, Janniger CK. Pityriasis alba. Cutis. Jul 2005;76(1):21-4. [Medline].
- Lucky AW, Grote GD, Williams JL, et al. Effect of desonide ointment, 0.05%, on the hypothalamic-pituitary- adrenal axis of children with atopic dermatitis. Cutis. Mar 1997;59(3):151-3. [Medline].
- Martin RF, Lugo-Somolinos A, Sanchez JL. Clinicopathologic study on pityriasis alba. Bol Asoc Med P R. Oct 1990;82(10):463-5. [Medline].
- Naseri M, Namazi MR. Isolated scalp involvement with pityriasis versicolor alba (pityrias versicolor albus capitis) in a patient from a dry, temperate region. Dermatol Online J. Aug 2003;9(3):17. [Medline]. [Full Text].
- Pinto FJ, Bolognia JL. Disorders of hypopigmentation in children. Pediatr Clin North Am. Aug 1991;38(4):991-1017. [Medline].
- Queille C, Pommarede R, Saurat JH. Efficacy versus systemic effects of six topical steroids in the treatment of atopic dermatitis of childhood. Pediatr Dermatol. Jan 1984;1(3):246-53. [Medline].
- Relyveld G, Menke H, Westerhof W. Progressive and extensive hypomelanosis and extensive pityriasis alba: same disease, different names?. J Eur Acad Dermatol Venereol. Nov 2006;20(10):1363-4. [Medline].
- Rigopoulos D, Gregoriou S, Charissi C, Kontochristopoulos G, Kalogeromitros D, Georgala S. Tacrolimus ointment 0.1% in pityriasis alba: an open-label, randomized, placebo-controlled study. Br J Dermatol. Jul 2006;155(1):152-5. [Medline].
- Thoma W, Kramer HJ, Mayser P. Pityriasis versicolor alba. J Eur Acad Dermatol Venereol. Mar 2005;19(2):147-52. [Medline].
- Vargas-Ocampo F. Pityriasis alba: a histologic study. Int J Dermatol. Dec 1993;32(12):870-3. [Medline].
- Whitmore SE, Simmons-O'Brien E, Rotter FS. Hypopigmented mycosis fungoides. Arch Dermatol. Apr 1994;130(4):476-80. [Medline].
- Wolf R, Wolf D, Trau H. Pityriasis alba in a psoriatic location. Acta Derm Venereol. Sep 1992;72(5):360. [Medline].
- Zaynoun S, Jaber LA, Kurban AK. Oral methoxsalen photochemotherapy of extensive pityriasis alba. Preliminary report. J Am Acad Dermatol. Jul 1986;15(1):61-5. [Medline].
Pityriasis Alba excerpt Article Last Updated: Nov 30, 2007
|
