Clinical Manifestations
The diagnosis of psoriasis is typically based on clinical findings, such as dermatologic history and physical examination; skin biopsy; identification of etiological factors such as drugs, stress and environment; and laboratory test results.1 Family history and age of onset can indicate clinical course, as early onset and family history are associated with more extensive and severe disease.2 Dermatologic psoriasis can present in various clinical patterns: psoriasis vulgaris (chronic stationary psoriasis, plaque-type psoriasis), guttate (eruptive) psoriasis, small plaque psoriasis, inverse psoriasis, erythrodermic psoriasis and pustular psoriasis (von Zumbusch, exanthematic and annular pustular psoriasis; palmoplantar pustulosis; acrodermatitis continua).3 Other types include seborrheic, napkin and linear psoriasis.3 Patients may experience a combination of types simultaneously or over time.4
The cutaneous lesions of chronic plaque psoriasis are typically sharply demarcated papules or raised plaques with a white scale and can vary in size.3 Lesions tend to be symmetrically distributed and can appear anywhere on the body, although they are most commonly located on the elbows, knees, scalp, buttocks and the lower lumbosacral and genital regions.3
In contrast to chronic plaque psoriasis, guttate psoriasis is characterized by eruption of small (0.5–1.5 cm in diameter), erythematous, scaling papules that develop as drop-like lesions.3,5 Occurring primarily in children and young adults, papules are located around the upper trunk and proximal extremities.3 Strongly associated with HLA-Cw6, papules frequently develop (flare or new onset) after streptococcal upper respiratory tract infection.3,5 Guttate psoriasis has a very rapid onset and responds well to therapy, particularly to treatment with ultraviolet light.5
In inverse psoriasis, lesions are typically sharply demarcated, erythematous and shiny or smooth plaques located in the intertriginous regions, such as the axilla, groin, submammary region, neck and navel, and scaling may be absent or minimal.3,5
Erythrodermic psoriasis is a more generalized and uniform psoriatic condition. Lesions are widespread and are characterized by a prominent, vivid erythema affecting all body areas, including the face, hands, feet, nails, trunk and extremities.3,5 Both acute and chronic forms have been described. In acute erythrodermic psoriasis, symptoms of widespread generalized red erythema and fine scales have a rapid and sometimes unexpected onset.3 The chronic form is characterized by plaques that worsen to involve nearly all skin surfaces.3 In this potentially life-threatening form of psoriasis, patients may experience vasodilation leading to hypothermia, excessive fluid loss, fever, malaise, shivers, hypohidrotic skin, lymphadenopathy and hair loss.3,5,6 Aggressive therapy and hospitalization are usually required to control erythrodermic psoriasis, as impaired hepatic and renal function and cardiac failure are common secondary presentations.5
Pustular psoriasis differs from the other types discussed above in that lesions are pustules, not plaques, that develop on normal or erythematous skin, with variable scale.3 Involvement might be limited to the soles and palms (palmoplantar psoriasis) or occur in a more generalized pattern (von Zumbusch).3 Clusters of sterile pustules 2–3 mm wide appear on the trunk and extremities, such as the nail beds, palms and soles.3 Fever may occur in episodic waves and severe, life-threatening complications, including bacterial superinfection, sepsis and dehydration, can develop.3 This presentation of psoriasis is rare, and is usually seen only in adult patients who have had previous forms of the disease.3 Palmoplantar psoriasis is characterized as demarcated, erythematous, pustular lesions localized to the palms and the soles of the feet, usually involving the thenar and hypothenar eminences of the hands, flexor aspects of fingers, heels and insteps.7
Nail involvement is frequently observed with psoriasis, with fingernail and toenail changes occurring in 50% and 35% of patients, respectively.8 Punctate nail pitting due to defective keratinization is a common feature.3,8 Consisting of single or multiple pits ranging in size from 0.5 to 2.0 mm, these alterations are more often seen on the fingers than on the toes.3 Other nail changes include onycholysis (separation of the nail plate from the nail bed), nail thickening, subungual hyperkeratosis, oil spots and salmon patches.3,8 A correlation between psoriatic arthralgias and fingernail involvement has been noted.3,8
- Callen JP, Krueger GG, Lebwohl M, et al; American Academy of Dermatology. AAD consensus statement on psoriasis therapies. J Am Acad Dermatol. 2003;49(5):897-899.
- Henseler T, Christophers E. Psoriasis of early and late onset: characterization of two types of psoriasis vulgaris. J Am Acad Dermatol. 1985;13(3):450-456.
- Gudjonsson J, Elder J. Psoriasis. In: Wolff K, Goldsmith L, Katz S, et al., eds. Fitzpatrick's Dermatology in General Medicine. 7th ed., vol. 1. New York: McGraw Hill Medical; 2008:169-193.
- Elder JT, Bruce AT, Gudjonsson JE, et al. Molecular dissection of psoriasis: integrating genetics and biology. J Invest Dermatol. 2009 Oct 8; Epub ahead of print.
- Peters BP, Weissman FG, Gill MA. Pathophysiology and treatment of psoriasis. Am J Health Syst Pharm. 2000;57(7):645-659; quiz 660-661.
- Boyd AS, Menter A. Erythrodermic psoriasis: precipitating factors, course, and prognosis in 50 patients. J Am Acad Dermatol. 1989;21(5 Pt 1):985-991.
- Kumar B, Saraswat A, Kaur I. Palmoplantar lesions in psoriasis: a study of 3065 patients. Acta Derm Venereol. 2002;82(3):192-195.
- Menter A, Gottlieb A, Feldman SR, et al. Guidelines of care for the management of psoriasis and psoriatic arthritis: Section 1. Overview of psoriasis and guidelines of care for the treatment of psoriasis with biologics. J Am Acad Dermatol. 2008;58(5):826-850.
