Psoriasis
Psoriasis: Excerpt from The 5-Minute Pediatric Consult
Albert C. Yan, MD
Psoriasis - BASICS
Psoriasis - description
Skin disease characterized by a chronic relapsing nature and, most commonly, clinical features of scaly, erythematous papules, and plaques with thick white scale, usually involving elbows, knees, and scalp (i.e., psoriasis vulgaris). Other variants include guttate, erythrodermic, and pustular psoriasis (see “Physical Exam” for details).
Psoriasis - epidemiology
- No gender predilection
- Onset of psoriasis is bimodal, commonly presenting in the third decade with a smaller second peak of onset in the 6th decade; however, it can present at any age, with a mean age of onset in children of 8.1 years.
- Earlier onset is associated with more severe disease.
Psoriasis - prevalence
Psoriasis is universal in occurrence, but the prevalence varies in different populations. The average prevalence in the US is estimated at 1–3%.
Psoriasis - risk factors
Psoriasis - genetics
Although psoriasis has a strong genetic influence, mode of transmission is not defined. It is likely multifactorial with more than one gene involved and is modified by environmental influence.
- 1/3 of patients with psoriasis report a relative with the disease.
- In family studies, 8.1% of children develop psoriasis when 1 parent is affected.
- When both parents have psoriasis, the affected percentage increases to 41%.
- In twin studies, 65% of monozygotic twins are concordant for the disease, while only 30% of dizygotic twins are concordant.
Psoriasis - pathophysiology
- Plaque-type psoriasis is characterized by a thickened parakeratotic epidermis with an absent granular layer above dermal papillae containing dilated tortuous capillaries.
- Collections of polymorphonuclear leukocytes extend from the dermal papillae into the epidermidis stratum corneum (i.e., Munro microabscesses).
- A mixed perivascular infiltrate is confined to the papillary dermis.
Psoriasis - etiology
The pathogenesis is unknown. Well-defined trigger factors include:
- Trauma to normal skin, producing psoriasis in the area (i.e., isomorphic response, sometimes called the Koebner phenomenon)
- Infections (e.g., upper respiratory infections, Streptococcus pyogenes, human immunodeficiency virus)
- Stress
- Winter in colder climates in northern hemisphere
- Some drugs (i.e., systemic corticosteroids, lithium, β-adrenergic blockers, NSAIDs, and antimalarials)
Psoriasis - associated conditions
Leukocytosis and hypocalcemia are associated with pustular psoriasis.
Psoriasis - DIAGNOSIS
Psoriasis - signs & symptoms
- Thick, flaky scales on skin
- In psoriasis vulgaris, sharply demarcated erythematous plaques with white scale are located most commonly on the elbows, knees, scalp, lumbar area, and umbilicus, but they can cover any surface and large areas of the body. Intertriginous regions are often involved, but scale is absent.
- Guttate psoriasis is a form that more often presents in children and young adults as small papules (0.5–1.5 cm), with limited scale over the trunk and proximal extremities, and is frequently associated with streptococcal infection.
- Erythema with variable scale involving the majority of the body accompanied by chills is characteristic of erythrodermic psoriasis.
- Generalized pustular psoriasis is the most serious variant, with sterile pustules as large as 23 mm arising on erythematous skin over large areas of the body. Usually such appearance is accompanied by high fever.
- A chronic and localized variant of pustular disease, however, involves only the palms and soles.
- Note: Classic plaque psoriasis is easily diagnosed, but variants and less virulent cases require careful examination for physical clues.
- Nails are frequently involved, with pinpoint pits, hyperkeratosis, and oil spots.
- Areas where disease is hidden are the retroauricular portion of the scalp and the perianal region.
- Swollen or deformed joints suggest associated psoriatic arthritis.
Psoriasis - history
- 1st appearance of eruption
- Area involved
- Recent illness, particularly sore throat
- Recent medications, particularly systemic steroids
- Any appearance of lesions with trauma to skin
- Joint pain
- Previous treatments and response
- Improvement with sun exposure
- Family history of psoriasis
Psoriasis - physical exam
- A complete cutaneous examination is necessary.
- Removal of scale on plaques produces bleeding points, a feature known as the Auspitz sign.
- The Koebner phenomenon may produce linear or geometric lesions corresponding to areas of trauma.
Psoriasis - tests
Psoriasis - lab
- Common finding: Elevated uric acid level. Streptococcus pyogenes infection is frequent in guttate disease, and throat culture is appropriate.
- Other laboratory values are generally within normal ranges. However, in more severe variants, anemia, elevated ESR, and decreased albumin levels may be found.
Psoriasis - differencial diagnosis
Classic plaque psoriasis is easily diagnosed. Variants of psoriasis, including guttate, erythrodermic, and pustular disease, are more difficult to recognize. The differential diagnosis varies with the type of psoriasis and includes:
- Nummular eczema
- Cutaneous T-cell lymphoma
- Tinea corporis
- Pityriasis rosea
- Pityriasis lichenoides et varioliformis acuta
- Secondary syphilis
- Atopic dermatitis
- Drug eruption
- Candidiasis
- Seborrheic dermatitis
Psoriasis - TREATMENT
Psoriasis - initial stabilization
- Therapy is delivered by topical medications, phototherapy, or systemic medications.
- Localized disease is treated with topical therapy and more diffuse disease with phototherapy.
- Systemic medications are reserved for resistant cases.
- Except in the most severe cases, therapy for children should be limited to topical medication and UVB phototherapy.
- General skin care should include gentle washing, soaking to remove scale, and application of emollients, preferably ointments and creams.
Psoriasis - special therapy
Phototherapy:
- UVB
- Administered between 3 and 7 times weekly in a booth with bulbs that emit the appropriate wavelength of UV radiation
- Effective for guttate and plaque psoriasis
- Average treatment time: 3 months, with gradual increases in time of exposure. Sunscreen should be used on the face.
- Narrow-band UVB represents a form of monochromatic UVB, using 311-nm wavelengths, appears to be a somewhat more effective form of delivering UVB phototherapy.
- PUVA (psoralen and UVB)
- PUVA and oral medications (e.g., methotrexate, acitretin) should be reserved for severe cases and carefully monitored by a dermatologist.
- Possible conflicts with other drugs: Photosensitizing medication (e.g., tetracyclines, sulfa derivatives, phenothiazines, among others) should be avoided with phototherapy.
- Topical:
- Topical corticosteroids
- Mid- to high-potency topical corticosteroid ointments are applied b.i.d.
- Mid-potency preparations (e.g., 0.025% fluocinolone ointment, 0.1% triamcinolone acetonide) are preferred in children.
- Low-potency corticosteroids (e.g., 1.0% and 2.5% hydrocortisone) are used on the face and intertriginous regions to prevent atrophy.
- Agents can also be found in shampoos (e.g., Dermasmoothe FS and Capex).
- Anthralin
- Anthralin, applied to plaques for a 30-minute application, should be carefully washed off.
- Lower concentrations used initially (e.g., 0.1%, 0.25%) are increased gradually as tolerated (e.g., 0.5%, 1.0%).
- Irritation and staining are common, so that the face and intertriginous regions cannot be treated with this approach.
- Calcipotriene:
- Calcipotriene ointment is a vitamin DIt is applied b.i.d., avoiding the face and intertriginous regions.
- Maximum weekly dosage in adults is 100 g.
- Rare cases of hypercalcemia have been reported.
- Although effective in children, safety guidelines have not been established.
- Tazarotene gel:
- A topical retinoid (i.e., 0.05% and 0.1%)
- Can be mildly to moderately irritating when used as monotherapy
- Often combined with topical steroids as adjunctive therapy applied once daily or b.i.d.
- Coal tar:
- A weak therapeutic agent as monotherapy
- More effective when combined with UVB phototherapy
- Used in various shampoo preparations
- Systemic agents:
- May be considered when the psoriasis is especially severe, or when joint symptoms are prominent. In these instances, consultation with a rheumatologist may be advisable.
- Methotrexate
- Isotretinoin or acitretin
- Cyclosporine
- Biologic agents, such as etanercept
- Systemic corticosteroid should be avoided since withdrawal from steroid may be accompanied by a pustular psoriasis flare.
Psoriasis - FOLLOW UP
- Topical therapy is administered chronically, with breaks to minimize side effects.
- Remissions occur in summer with sun exposure, and medications may often be discontinued.
- The average treatment course with UVB therapy is 3 months; if the patient’s skin clears, treatment may be followed by an average remission period of 5 months.
Psoriasis - disposition
Psoriasis - issues for referral
- Pustules, a significant increase in degree or extent of erythema, or fever suggest progression of the disease to more serious variants and may require hospitalization and systemic therapy.
- Erythrodermic psoriasis may require hospitalization to address issues of impaired skin integrity, such as fluid–electrolyte imbalances, hypothermia, and sepsis.
Psoriasis - prognosis
- Once psoriasis appears, it generally persists throughout life.
- Spontaneous remissions of variable length and frequency occur but are unpredictable.
- Response depends on potency of medication and frequency of treatment.
- Improvement with topical medication is obvious at 2 weeks, and usually peaks at 2 months.
- 1 month of UVB therapy may produce a decrease in disease.
- If therapy is too aggressive, disease may worsen, due to irritation.
- Scrubbing by the patient to remove scales also irritates the disease.
- Psychologic aspects of the disease, particularly in children, should be addressed.
Psoriasis - bibliography
- Capella GL. Finzi AF. Psoriasis and other papulosquamous diseases in infants and children. Clin Dermatol. 2000;18:701–709.
Christophers E, Sterry W. Psoriasis. In Fitzpatrick TB, Eisen AZ, Wolff K, et al., eds. Dermatology in General Medicine. 4th ed. New York: McGraw-Hill, 1993:489.- de Jong EM. The course of psoriasis. Clin Dermatol. 1997;15:687–692.
- Farber EM. Early intervention can reduce risks for problems later. Postgrad Med. 1998;103:89–92, 95–96, 99–100 passim.
- Leman J, Burden D. Psoriasis in children: A guide to its diagnosis and management. Paediatr Drugs. 2001;3:673–680.
- Stern RS. Epidemiology of psoriasis. Dermatol Clin 1995;13:717–722.
Psoriasis - CODES
Psoriasis - icd9
696 Psoriasis and related disorders
Psoriasis - FAQ
- Q: Will my disease get worse?
- A: It is impossible to predict the course of any patient’s disease, because it is influenced by both heredity and everyday factors in the environment. While there is no cure, with treatment the disease can be kept under control. Remissions do occur and may be for prolonged periods of time.
- Q: When my disease is in remission, what can I do to prevent it from returning?
- A: Avoiding trauma and keeping skin moist are important. In the summer, controlled sun exposure is helpful. You may have to continue other treatments at less frequent intervals. Any cases of sore throat should be cultured and treated if streptococcal disease is present. However, frequently it is impossible to prevent recurrence of the disease.
- Q: Will my other children get psoriasis?
- A: If neither parent has psoriasis, the chances are <10% that another child will develop the disease; if 1 parent is affected, the chances increase to 15%; if both parents are affected, the chances are 50%. Therefore, unless both parents are affected, it is more likely that other children will not get psoriasis.
- Q: Does stress make psoriasis worse?
- A: Some studies have suggested that flare-ups of psoriasis are associated with increased stress. It is difficult to evaluate whether stress is the cause or the result of the disease. Do all you can to reasonably relieve stress, but do not focus on this as the cause of your psoriasis.
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Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About Psoriasis
More Medical Textbooks Online about Psoriasis
Review other book chapters online related to Psoriasis:
Medical Books Excerpts
- Psoriasis
- "Professional Guide to Diseases (Eighth Edition)" (2005)
- [ read ]
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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