Psoriasis Flashcards
Psoriasis
o Psoriasis is a genetic disease of dysregulated inflammation due to T cell activation and cytokine release
o Immune-mediated skin and/or joint disease in which intralesional inflammation primes basal stem keratinocytes to hyperproliferate
o What the heck does that mean????
Skin cell turnover is usually 26-28 days. In psoriasis, it is 3-4 days
o Lifelong disease with chronic, recurrent exacerbations and remissions
o The lesions of psoriasis are distinctive
Begin as red, scaling papules that form round to oval plaques
Scale is silvery white
o Chronic, inflammatory, well-defined plaques are the most common presentation
o Lesions are usually symmetrically distributed
o Most commonly occur on the scalp, nails, extensor surfaces of the limbs, umbilical region, and sacrum
o Psoriasis is a complex immune-mediated disease. Genetic factors play an important role in susceptibility to psoriasis. The psoriasis-susceptibility (PSORS1) locus within the major histocompatibility complex (MHC) on chromosome 6p21 is considered the major genetic determinant of this disease.
epidemiology of psoriasis
o 1 to 2% of the US population has psoriasis
o There may be millions who are genetically predisposed to psoriasis, only needing the correct environmental factors to precipitate the disease
o More than 30% have their first episode before age 20
the peak times for disease onset are young adulthood (ages 20 to 30 years) and late middle age (ages 50 to 69 years)
Mean age of onset is 27
o Males = females
o Low incidence in North American and West African black persons, American Indians
o First degree relatives are at an increased risk
presentation of psoriasis
o Most will present with a long-time “rash” that has never really subsided and slowly developed
o Usually begins on the scalp or elbows and may remain localized in the original region for years
o Chronic disease may also be entirely limited to the finger nails
o Psoriasis can also be exanthematous, with a sudden onset of numerous guttate (droplike) lesions
o Lesions usually last months
o Once expressed, psoriasis is likely to follow a relentless, waxing and waning course
o Itching and burning, may present and can cause extreme discomfort
clinical subtypes of psoriasis
o Chronic Plaque Psoriasis o Guttate o Pustular o Erythrodermic o Inverse o Nail Psoriasis
plaque psoriasis
-Chronic plaque psoriasis – Most common subtype
Chronic, defined plaques
Thick “Salmon pink” scaly lesions that tend to be symmetrically distributed
Look for a deep, rich red area of inflammation under the scales
Plaques tend to remain stable for months to years
Very common on the elbows, knees and/or scalp
guttate psoriasis
o Guttate Psoriasis
o Scaling papules that suddenly appear on the trunk and extremities, not including the palms and soles
o Typical lesions are the size of water drops, 2-5mm
o An episode of guttate psoriasis is often the first indication of the patients propensity for the disease
o Strep pharyngitis or viral URI often will precede this eruption by 1 to 2 weeks
o MUST take a throat culture in case of strep
o If positive, treat with 10 days of amoxicillin or Augmentin
If PCN allergic, use azithromycin for 5 days
o Guttate may resolve spontaneously in weeks to months
o Responds very well to treatment
pustular psoriasis
o Serious and sometimes fatal disease
o Look for erythema that suddenly appears in the flexural areas
o Numerous tiny, sterile pustules evolve from an erythematous base and coalesce into lakes of pus
o This patient is usually toxic and febrile with a leukocytosis
o Causes of this type include pregnancy, infection and withdrawal of topical and systemic corticosteroids
erythrodermic psoriasis
o Uncommon manifestation
o Generalized erythema and scaling from head to toe
o Patients are at high risk for complications related to an inadequate barrier function such as sepsis
o Electrolyte abnormalities secondary to fluid loss
o These patients have a universal skin barrier dysfunction – this variant is an emergency
o May be the initial manifestation of psoriasis but usually occurs in patients with previous chronic disease
o Precipitating factors include administration of oral steroids, overuse of topical steroids, severe emotional stress, preceding illness or infection
o Inpatient management involving a dermatologist is needed
o Treatment includes bed rest, utilization of burrows solution or colloidal oatmeal baths, liberal use of emollients, increased intake of protein and fluids, antihistamines for pruritus, NO topical steroids as this may exacerbate the flare, and in severe cases, hospitalization.
o Drugs with rapid efficacy include cyclosporine, remicade, acitretin, methotrexate
inverse psoriasis
o Gluteal fold, axillae, groin, submammary folds, retroauricular fold, and the glans of the uncircumcised penis may be affected
o Lesions are smooth, red, sharply defined with a macerated surface, often with on odor
o As with typical psoriatic plaques, the margins are distinct and sharply circumscribed
o Pustules beyond the plaque border suggest secondary yeast infection
o Cracking and fissures are common
o Often confused with a candida infection
o A psoriasis diagnosis often becomes apparent when topical and oral anti-yeast medications fail
o Watch for superimposed candidal infections in diabetic patients and chronic topical steroid use
nail psoriasis
o Nail pitting is the most frequent nail abnormality
o Onycholysis or separation of the nail from the nail bed
o Oil Spot Lesions – look for a translucent yellow-red discoloration that resembles a drop of oil beneath the nail plate
Oil spot/nail pitting – pathognomonic for psoriasis
o Nail disease often provides valuable evidence of psoriasis when skin lesions are difficult to diagnose clinically or are absent
o Nail disease is more common in patients with psoriatic arthritis
o If they have nail psoriasis, a lot of times this means that they could have psoriatic arthritis at the same time
psoriatic arthritis
o This is a chronic inflammatory arthropathy of the peripheral joints, spine, soft tissue (ANA and RF negative)
o Onset can occur at any age: most common between 20-40
o Occurs in ~30% of psoriasis patients and precedes the skin manifestations in ~15%
o Look for asymmetric swelling of one or two joints (most common)
o Swollen finger joints, sausage finger or toe (dactylitis)
o 10% have DIP involvement often with associated nail changes
o 20% of PsA patients have spinal arthritis that can be highly debilitating
o 5% have a mutilating type that can completely destroy a joint
o Soft tissue inflammation presents as enthesitis (inflammation at the site of tendon insertion into a bone). Look for a swollen area at the distal end of the Achilles
o Hand XRAY – “Pencil in Cup” Deformity
o Refer to rheumatology to salvage joint function
exacerbating factors of psoriatic arthritis
o Smoking – higher prevalence of psoriasis in both current and former smokers
o Obesity – genetically susceptible patients have more severe disease as their BMI increases
o Drugs – Lithium, beta blockers, antimalarial agents and systemic steroids can precipitate or exacerbate psoriasis
o EtOH – may cause more severe disease. Also, decreases the response to conventional treatment possibly due to less compliance
o HIV – can often be the presenting sign of HIV infection
When associated with HIV, psoriasis is often severe, with palmar-plantar involvement, nail disease, arthritis and widespread disease
associated comorbidities of psoriatic arthritis
o Increased risk of cardiovascular disease
o Crohn’s and ulcerative colitis – 3.8 and 7.5 times more likely
o Increased incidence of HTN and DM2
o Vitamin D deficiency
o Higher prevalence of metabolic syndrome
o Depression – prevalence of depression in psoriasis patients may be as high as 60%
o Elevated rates of poor self-esteem, sexual dysfunction, and anxiety
o Another reason I love dermatology…..WE have the chance to fix depression, alcoholism, low self esteem, and anxiety. Major quality of life improvement!!
auspitz phenomenon
removal of scale results in tiny blood droplets
koebner phenomenon
psoriasis can develop at the site of physical trauma (scratching, sunburn, surgery)
