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Flashcards in Psoriasis Deck (38)
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Describe the appearance of psoriasis

Chronic, immune mediated disease

Sharply demarcated erythematous plaque with micaceous (silver) scales


How does psoriasis develop?

Polygenic predisposition + AI + environmental triggers


What genetic factor causes early onset psoriasis?

HLA-Cw6 (Chromosome 6)


What % of psoriasis suffers have a family history of both parents having psoriasis?



What % of psoriasis suffers have a family history of psoriasis?



What % of psoriasis suffers have a family history of one parent having psoriasis?



What is the psoriasis susceptibility regions?

Psoriasis susceptibility regions PSORS1-9


What genetic factors are involved in psoriasis?

Psoriasis susceptibility regions PSORS1-9
HLA-Cw6 (Chromosome 6)


What environmental factors are known to trigger psoriasis?

– Infection
– Drugs e.g. beta blockers
– Trauma – scratching can induce excoriation and lesions
– Sunlight
- stress


Describe the histology of psoriasis

Hyperkeratosis (thickening of stratum corneum)

Neutrophils in stratum corneum (munro’s microabcesses)

Psoriasiform hyperplasia: Acanthosis (thickening of squamous cell layer) with elongated rete ridges

Dilated dermal capillaries

T cell infiltration


What are munro’s microabcesses?

Neutrophils in stratum corneum (munro’s microabcesses) seen in psoriasis


What medications are linked to causing psoriasis?

beta blockers, Ca channel blockers


What are 2 emergency forms of psoriasis?

– Erythroderma (>80% BSA covered) – emergency situation
– Pustular psoriasis – another emergency form


What is seen on the skin when you examine a psoriasis patient?

– Sharply demarcated, erythematous, papulosquamous (elevated squamous) plaques
– Numerous small, widely disseminated papules and plaques

If >80 BSA covered or pustular, clinical emergency


What is seen on the nails when you examine a psoriasis patient?

onycholysis (separation of nail from nail bed)
pitting (most common)
oil spots


Describe Koebner phenomenon

Koebner phenomenon - appearance of lesions along a site of injury


What is Woronoff’s ring?

Woronoff’s ring - blanched halo of approximately uniform width surrounding psoriatic lesions after phototherapy or topical treatments


What type of psoriasis is often seen acutely following an infection, particularly strep infection?

Guttate psoriasis


Describe chronic plaque psoriasis

Chronic Plaque Psoriasis: symmetrical, extensor surfaces
• Plaque psoriasis is the most common form of the disease and appears as raised, red patches covered with a silvery white buildup of dead skin cells.
• These patches or plaques most often show up on the scalp, knees, elbows and lower back. They are often itchy and painful, and they can crack and bleed.


Describe the appearance of Guttate psoriasis

Small (<5mm), salmon-pink (or red) spots usually appear suddenly on the skin two to three weeks after a streptococcal infection, such as strep throat or tonsillitis. The drop-like lesions are usually itchy.


What type of psoriasis affects the skin on the palms and soles, making them appear thick, scaly and red with yellowish brown lesions at the edges?

Palmo-plantar Psoriasis/pustulosis


What type of psoriasis is often associated with smoking and sterile inflammatory bone lesions?

Palmo-plantar Psoriasis/pustulosis


Describe Flexural/Inverse Psoriasis

o Less scaly – flexures cause constant friction so appear smoother
o Can be triggered or superinfected by localised dermatophyte, candidal or bacterial infection – these are also differential diagnoses. Makes it often confused with infections
o Sometimes called inverse psoriasis and describes psoriasis localised to the skin folds and genitals.


What would you suspect if a patient presents with an acute onset of generalised red, tender patches, which on closer inspection of the patches multiple yellow pustules are seen?

Pustular Psoriasis - clinical emergency

o Sterile pustules, sometimes systemic symptoms
o Generalized so not limited to palms and soles of feet
o Linked to pregnancy, rapid taper/stop steroids, hypocalcaemia, infections
o Overlap with acute generalized exanthematous pustulosis (AGEP; pustular drug eruption reaction)


What can trigger pustular psoriasis?

Linked to pregnancy, rapid taper/stop steroids, hypocalcaemia, infections


What condition overlaps with pustular psoriasis?

Overlaps with acute generalized exanthematous pustulosis (AGEP; pustular drug eruption reaction)


Describe the features of Erythrodermic psoriasis

Patient presents feeling shivery and generally unwell.
O/E More than 80% of his body surface area is erythematous, with fine scale.
Pyrexial and has a low blood pressure.


What are some differential diagnoses for psoriasis?

• Seborrhoeic dermatitis – chronic form of eczema; red itchy skin over sebaceous glands, scaly but appear more greasy (except sebopsoriasis!)
• Lichen planus - small, flat-topped, polygonal bumps that may coalesce into rough, scaly plaques on the skin. Very itchy
• Mycosis fungoides - common form of cutaneous T-cell lymphoma; non-resolving psoriasis like presentation
• Bowens disease – early sign of skin cancer, red scaly patch
• Drug eruption – squamous rash
• Infection
• Secondary syphilis – small painless sores, not scaly
• Contact dermatitis – inflammation caused by irritants
• Extramammary pagets – adenocarcinomas secondary to primary tumours, rare


What does a drug eruption look like?

Squamous rash


What treatments for psoriasis are given from your GP?

o Emollients (standard) - creams or ointment
o Soap substitutes
o Vitamin D3 analogues: inhibit epidermal proliferation
o Coal Tar creams
o Topical Steroid
o Salicylic acid (keratolytic, descaling agent) – special cases with severe scaling. Used alongside other treatments