Table 3. Diagnosis of Psoriasis*: Clinical Appearance and Types
PresentationFeaturesAdditional FeaturesLocationTreatment(s)
Plaque (psoriasis vulgaris is most common)Well-demarcated papule or plaque with silvery scale and punctuate bleeding when peeled (Auspitz's sign)Koebner's phenomenon, which is the development of psoriasis in areas of trauma16Knees, elbows, trunk (extensor surfaces), nape of neck, postauricular, lumbosacral area, scalp, feet, hands, penis16Topical and/or systemic, depending on severity and recalcitrance
Intralesional steroids for local recalcitrant disease
NailProximal nail matrix produces defects in keratinization that are translated as the nail grows out from the cuticle in the form of pits <1 mm in diameter
Psoriasis of the nail bed results in oil spots. Patients also get splinter hemorrhages.17
Subungual hyperkeratosis (onchyolysis) starts as the free nail separates from the nail bed and can be demarcated by a yellow band; this allows for material from the nail bed to accumulate under the nail.16,17
Consider possible future development of PsA.
Fingernails and/or toenailsIntralesional steroids, CsA18
Inverse (uncommon)Painful, well-demarcated, symmetric, erythematous papules and plaques that may become macerated, often eroded, or secondarily infected because of location19Intertriginous regions of the body: inframammary, neck, axillary, inguinal crease, and interglutealTopical
Erythrodermic>90% Involvement of BSA
Acute: develops over days, can be severe and even life threatening because of greater stress on the heart and other metabolic resources of the body
Chronic: develops more slowly over months to years
Acute form can result in hospitalization and can be life threatening if severe because of loss of fluids (electrolytes, water, proteins) and unstable body temperature20WidespreadSystemic (acetretin,18 MTX, CsA18)
Pustular (generalized type; rare; 4 types)Erythema and sterile pustules sometimes in preexisting plaques or in annular lesionsSome can have metabolic disturbances.19 Causes include pregnancy, rapid steroid taper, infections, hypocalcemia, or topical local irritants19Widespread in flexuresSystemic (acitretin18) or biological
Palmar/plantar pustularVesicles lead to pain and/or significant itch in involved areas.Typically recalcitrant because of the thickness of the skin of the palms and soles, limiting penetration of topical treatments and trauma to hands and feet, causing the Koebner phenomenonHands/feetUV light (PUVA/UVB), acitretin,18 CsA18
GuttateAbrupt eruption of psoriasis that is characterized by 2- to 5-mm teardrop-shaped papules.Preceded by a streptococcal infection or drug-induced (carbamazepine, α-interferon, antimalarials, abrupt cessation of systemic corticosteroids, lithium, β-blockers)2Trunk and extremitiesWith UV light and withdrawal of offending drugs or resolution of streptococcal disease, some patients have resolution.
Some patients will go on to have psoriasis later in life, with most developing plaque-type psoriasis.
  • * Psoriasis is a disease that is diagnosed clinically, but if the condition fails to respond to therapy or lesions do not appear classic, a biopsy or dermatology referral may be warranted.

  • CsA, cyclosporin A; MTX, methotrexate; PsA, psoriatic arthritis; UV, ultraviolet; PUVA/UVB, psoralen + ultraviolet A/ultraviolet B; BSA, body surface area.