Acrodermatitis continua of Hallopeau

Pustular psoriasis confined to distal fingers or toes, sometimes to just one digit

Replaced by scale and crust when it resolves

Treatment: Systemic retinoids, vitamin D3 analogs (eg, calcipotriol), topical corticosteroids, systemic immunosuppressants (eg, biologics, small molecules)

Prognosis: Waxes and wanes

Erythrodermic psoriasis

Gradual or sudden onset of diffuse erythema, usually in patients with plaque psoriasis (possibly the first manifestation of erythrodermic psoriasis); typical psoriatic plaques less prominent or absent

Most commonly triggered by inappropriate use of topical or systemic corticosteroids or light therapy

Treatment:

Prognosis: Good with elimination of triggering factors

Generalized pustular psoriasis

Explosive onset of widespread erythema and sterile pustules

Treatment:

Prognosis: If untreated, can be fatal due to high-output heart failure

Guttate psoriasis

Abrupt appearance of multiple plaques 0.5 to 1.5 cm in diameter, usually on the trunk in children and young adults after streptococcal pharyngitis

Treatment: Antibiotics for underlying streptococcal infection as needed

Possibly topical and/or systemic treatment after antibiotics

Prognosis: Excellent, often with permanent cure

May progress to plaque psoriasis

Inverse psoriasis

Psoriasis of intertriginous areas (usually the inguinal, gluteal, axillary, inframammary, and retroauricular folds and the glans of the uncircumcised penis)

Possibly formation of cracks or fissures in the center or edge of involved areas

Possibly absence of scales

Treatment: Topical corticosteroids of minimal effective potency, with or without vitamin D3 analogs (eg, calcipotriol)

Prognosis: Waxes and wanes

Nail psoriasis

Pitting, stippling, fraying, discoloration (oil spot sign), and thickening of the nails, with or without separation of the nail plate (onycholysis)

May resemble a fungal nail infection

Affects 30–50% of patients with other forms of psoriasis

Treatment: Responds best to systemic therapy with immunosuppressants (eg, biologics, small molecules)

For brave or stoic patients, possibly intralesional injection of nail folds with corticosteroids

Prognosis: Often unresponsive to treatment

Palmoplantar psoriasis

Hyperkeratotic, discrete plaques on palms and/or soles that tend to become confluent

Treatment:

Prognosis:

Waxes and wanes

Rarely resolves completely, even with treatment

Plaque psoriasis

Gradual appearance of discrete, erythematous papules or plaques covered with thick, silvery, shiny scales

Lesions that remit and recur spontaneously or with appearance and resolution of triggers

Treatment: Topical corticosteroids of minimal effective potency, with or without vitamin D3 analogs (eg, calcipotriol)

Prognosis: Waxes and wanes

Palmoplantar pustulosis (pustular psoriasis of the palms and soles)

Gradual appearance of deep pustules on palms and soles

Flares may be painful and disabling

Typical psoriatic lesions possibly absent

Treatment: Systemic retinoids or psoralen plus ultraviolet A (PUVA) therapy

Prognosis: Waxes and wanes