Types of Pustular Psoriasis
In pustular psoriasis, the skin will develop pus-filled lesions called pustules. Although pustules are typically associated with infection, in pustular psoriasis the lesions are formed as the result of inflammation, usually in the absence of infection. Both generalized and localized types of pustular psoriasis are recognized.Generalized Pustular Psoriasis
Generalized pustular psoriasis (GPP) has four recognized patterns:- von Zumbusch pattern: a whole-body painful eruption accompanied by systemic symptoms such as fever and malaise. Innumerable pustules form which can sometimes coallesce into larger "lakes of pus".
- Annular pattern: growing and spreading rings with an advancing edge of pustules. The lesions enlarge and spread over hours to days with central clearing. Systemic symptoms may again be seen.
- Exanthematic type: This is usually an abrupt eruption of tiny pustules, typically without systemic symptoms and with relatively rapid clearing. This may be a type of drug eruption when associated with a medication such as lithium. I have also seen this happen more than once with Cipro. Another name for this rash in the setting of a drug eruption is acute generalized exanthematous pustulosis.
- "Localized" pattern: In patients with widespread plaque type psoriasis, pustules may develop within or at the edges of plaques. This can be seen with irritating treatments such as coal tar or even rapid withdrawlal of potent topical steroids.
Localized types of pustular psoriasis
Pustular psoriasis can be limited to the palms and soles or just the fingertips/ends of toes. When the palms and soles are involved,the condition is sometimes termed palmoplantar pustulosis. Fintertip pustular psoriasis, called Acrodermatitis continua of Hallopeau can be accompanied by complete shedding of the nails.How to Avoid Pustular Psoriasis
Several factors have been known to increase the risk of the various types of pustular psoriasis and avoiding or minimizing these may be helpful:- Avoid systemic corticosteroids like injections or oral prednisone for treating psoriasis
- Avoid abruptly stopping any psoriasis treatment without speaking with your doctor first -- a transition to another drug may require an overlap period of using both treatments to avoid a possible flare or pustular eruption
- Avoid those drugs which are know to flare pustular psoriasis such as lithium, beta-blockers and others.
- Avoid irritating treatments such as coal tar medications when treating a severe, whole body psoriasis such as exfoliative erythroderma.
source: van de Kerkhof, Peter CM. Psoriasis. in: Dermatology. Bolognia JL, Jorizzo JL, Rapini RP eds. pages 131-132 Mosby (Elsevier)New York 2003
