CHAPTER 14 Psoriasis Flashcards
what are the triggers of psoriasis ?
Triggering factors, both external (directly interacting with the skin) and systemic, can elicit psoriasis in genetically predisposed individuals.
there is external and internal triggering factors
what is the external triggering factor for psoriasis ? % of patients suffering psoriasis that can experience this ?
The Koebner or isomorphic phenomenon, i.e. the elicitation of psoriatic lesions by injury to the skin, is observed in ~25% of patients with psoriasis.
Do patients that are KOEBNER - become KOEBNER + ?
YES! particular patient may be “Koebner-negative” at one point in time and later become “Koebner-positive”. The Koebner phenomenon suggests that psoriasis is a generalized skin disease that can be triggered locally
is Koebner induced by trauma only? or can it be produced by other triggers? if yes - please mention some ?
Psoriatic lesions can also be induced by other forms of cutaneous injury, e.g. sunburn, morbilliform drug eruption, viral exanthem.
what is the lag time for koebner ? ( from trauma to appearance of skin lesions)
The lag time between the trauma and the appearance of skin lesions is usually 2–6 weeks.
what are the Systemic triggering factors for psoriasis ? mention them and give examples
- Infections (particularly bacterial infections, may induce or aggravate psoriasis. Provoking infections have been observed in up to 45% of psoriatic patients. Streptococcal infections, especially pharyngitis -Streptococci can also be isolated from other sites of infection, e.g. dental abscesses, perianal cellulitis, impetigo.
- ENDOCRINE Hypocalcemia :
triggeers generalized pustular psoriasis,
active vitamin D3:
analogues improve psoriasis, abnormal vitamin D 3 levels have not been shown to induce psoriasis.
pregnancy : 50 % experience improvement, but there are some that experience pustular psoriasis - associated with hypocalcemia ( impetigo herpetiformis - sterile pustules )
-HIV
- PSYCHOGENIC STRESS
DRUGS ( see another slide)
what are the drugs that illicit psoriasis ?
can you explain how is it possible for one of these agents to cause psoriasis aggravation ?
IFN
LITHIUM
ANTI PD1 ( anti programmed death 1)
BB
Plaquinil
The association with immune checkpoint inhibitors may be related to increased levels of IL-6 and thus illicit psoriasis
can steroids illict psoriasis ?
steroids combined with vitamin d derivatives are therapeutic but it is important to know that SYSTEMIC STEROIDS if they are tapered rapidally this can trigger psoriasis
a patient walks into your clinic - he was treated with dupixent for atopic dermatitis. on your examination you notice new psoriasiform lesions what is this called ?
DUPILUMAB is IL4a blocker.
In addition, patients with atopic dermatitis who receive dupilumab can develop psoriasiform lesions, presumably due to a phenotypic shift from predominantly Th2-mediated inflammation to a Th1 immune response.
what are the other behavioral factors that could trigger psoriasis ?
Obesity, increased alcohol consumption, and smoking have all been associated with psoriasis.
However, other studies have suggested that weight gain often precedes the development of psoriasis
halting smoking could cause revertion of the lesions
common features to all psoriatic lesions?
erythema, thickening, and scale.
what is type 1 psoriasis associated with ?
- HLA-Cw6+
- early onset
- more widespread
- frequent recurrences.
compared to those with type II psoriasis.
what is the woronoff ring?
psoriatic lesions are sometimes surrounded by a pale blanching ring, which is referred to as Woronoff’s ring.
Psoriasis is characterized by erythema , thickening and scale. what are the histological findings that correlate to these clinical lesions
ERYTHEMA –> elongated dilated capillaries
THICKENING —> Epidermal acanthosis and cellular infiltrate
Scale —-> Abnormal keratinization
what is the Auspitz sign?
If the superficial silvery white (micaceous) scales are removed, then a wet surface is seen with characteristic pinpoint bleeding. This finding, called Auspitz sign, is the clinical reflection of elongated vessels in the dermal papillae together with thinning of the suprapapillary epidermis.
what could indicate an unstable phase of the disease in a psoriatic patient?
Pinpoint papules surrounding existing psoriatic plaques indicate that the patient is in an unstable phase of the disease.
how do the expanding psoriatic lesions look like ?
expanding psoriatic lesions are characterized by an active edge with a more intense erythema.
Unstable psoriasis ?
Unstable psoriasis represents an exacerbation of psoriatic disease and initially mimics guttate forms, presenting with diffuse small droplet-like papules. These lesions progress within days to weeks to enlarge or coalesce into larger plaques or evolve into pustular lesions or erythroderma.
differentiation of pustular psoriasis from pustules formed due to unstable psoriasis can be a challenge
what is PASI and why was it developed ?
Due to the fact that the the percentage of body surface area involved does not reflect the severity of the individual lesions with respect to erythema, induration, and scaling, the Psoriasis Area and Severity Index (PASI) was formulated
What are the Scoring systems used for psoriasis
- PASI
- Palmoplantar Psoriasis Physician Global Assessment
- Psoriasis Scalp Severity Index
- Nail Psoriasis Severity Index
- Static Physician Global Assessment of Genitalia
What is Guttate psoriasis ? which population does it affect the most ?
More commonly seen in children and adolescents
Usually there is URTI prior to the appearance of the lesion
- in over half of the patients there is Antistreptolysin O posiitvity or Anti DNase B, Streptozyme + (indicating recent infection)
what do you know about Erythrodermic Psoriasis?
- characterized by generalized erythema and scaling, and its onset can be gradual or acute.
Although there are many causes of erythroderma , clues to the diagnosis of psoriatic erythroderma include PREVIOUS PLAQUES in classic locations, characteristic NAIL CHANGES and FACIAL SPARING
CARD14-associated papulosquamous eruption, what is special about this eruption ?
this eruption happens due to CARD14 mutation. the patient looks erythrodermic with alot of scale
here there is features of both psoriasis and pityriasis rubra pilaris (PRP).
the features of this eruption include :
- family history of psoriasis or PRP
- lack of response to topical and systemic therapy for psoriasis
- it appears at an early stage and involves face ears and cheeks, chin and ears.
- surprising response to improvement with ustekinumab
what does the CARD14-associated papulosquamous eruption respond to (in regards to therapy )?
it doesnt respond to the topical and systemic therapy of psoriasis —> but surprisingly responds to USTEKINUMAB.
usually NF-κB is upregulated in the skin of those with this disorder and CARD14 mutations—–> Resulting in increase in IL-8 and CCL20 —-> recruit and activate inflammatory cells —>The latter leads to production of IL-23 by dendritic cells and IL-17 and IL-22 by T cells
this explains why stelara ( Il23 blocker) results in improvement of this eruption