Rupioid psoriasis is a form of psoriasis with hyperkeratotic skin lesions.

Risk factors:

(1) HIV

(2) medications (lithium, hydrochlorothiazide, beta-blockers)


Clinical features:

(1) circular plaques with concentric, cone-shaped hyperkeratosis resembling limpet shells

(2) erythematous base

(3) poor response to topical treatment

(4) responds to systemic agents


Other types of hyperkeratotic psoriasis are ostraceous and elephantine forms.


Histologic features:

(1) psoriasiform hyperplasia

(2) confluent parakeratosis

(3) neutrophils within the stratum corneum

(4) diminished granular layer


Differential diagnosis:

(1) secondary syphilis

(2) scabies

(3) disseminated histoplasmosis

To read more or access our algorithms and calculators, please log in or register.