psoriasis Flashcards
define psoriasis
A chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
1) Epidermal hyperproliferation — cells multiplying too quickly.
2) Abnormal keratinocyte differentiation — cells not maturing normally.
3) Lymphocyte inflammatory infiltrate — the presence of cells which cause inflammation
types of psoriasis and their descriptions
Chronic plaque psoriasis - MOST COMMON TYPE,
Guttate – raindrop lesions
Seborrheic – naso-labial and retro auricular
Flexural/inverse – body folds
Pustular – palmar/plantar or generalised
Erythrodermic – total body redness
causes of psoriasis
Complex interaction between genetic, immunological and
environmental factors
familial
the layers of the skin and function
epidermis
dermis
- nerves
- sweat glands
- lymph vessels
- blood vessels
hypodermis
- fat & connective tissue
- anchors skin to muscle
layers of the epidermis
stratum basale - new keratinocytes
stratum spinosum
stratum granulosum - keratinisation - create the epidermal skin barrier
stratum lucidum - only found in palms and soles of the feet
stratum corneum - new kerationocytes push up and old ones dies and fall off
pathophysiology of psoriasis
blood vessels dilate in the dermis
delivers more
immune cells to the epidermis
colect in str cor
keratinocytes proliferate abnormally
thins basale layer
thicken corneum and spinosum layer
- produce more keratin
retain nuclei
do not adhere properly
what is auspitz
localised spots of bleeding
features of plaque psoriasis
falttened areas of elevation
inflamed and red - dialted blood vessels
white-silver plaques
scalp and tensor regions
features of guttate psoriasis
small, red individual spots
raindrop
trunk and limbs
starts in childhood - sometimes triggered bu infection
features of inverse psoriasis
smooth and shiny red lesions
within skin folds - groins, armpits
features of pustular soriasis
red skin
white elevations of pus - formed from dead immune cells
tender
hands and feet
features of erythrodermic psoriasis
extremely itchy and painful
scales fall off in sheets
triggers factors of psoriasis
- trauma – koebner phenomenon - this is when lesions are produced in areas where you don’t normally see psoriasis
- streptococcal infection ass. With guttate psoriasis esp with URT ie. Tonsillitis
- drugs
o lithium, antimalarial drugs such as chloroquine, beta-blockers, nonsteroidal anti-inflammatory drugs (NSAIDs), angiotensin-converting enzyme (ACE) inhibitors, trazodone, terfenadine, and antibiotics such as tetracycline and penicilli - stress
- alcohol – trigger by impairing skin barrier function, altering immune function and keratinocyte activity
- smoking – induction of oxidative damage and stimulation of pro-inflammatory cytokines
o localised pustular psoriasis - UV exposure – may precipitate generalised pustular psoriasis
- Hormonal changes – puberty, post-partum and during menopause
- HIV infection and AIDS
- Pscyh stress
associated conditions with psoriasis
• Psoriatic arthritis
o Inflam pain or peripheral joint swelling affecting the knees, ankles, hands and feet or dactylitis
o Night-time pain in the axial skeleton, enthesitis tendon insertions
• Metabolic syndrome
o obesity, hyperlipidaemia, hypertension, type 2 diabetes mellitus, and non-alcoholic fatty liver disease
- nails psoriasis - pitting, ridging or onycholysis
- IHD
- UBD
- Anxiety and depression
- VTE
- Non-melanoma skin cancer
what to ask a patient suspecting psoriasis
- Lesions can sometimes be itchy, burning or painful
- Systemic illness signs
- Known trigger factors
- Have they tried any over the counter medications
- Symptoms relating to ass conditions – joint pain, nails PSORIASIS EPIDEMIOLOGY SCREENING TOOL – score 3 or more REFER TO a RHEUMATOLOGIST
- Persons perception of psoriasis – 7-point patient’s global assessment
- Physical, psychological and social impact of psoriasis on the person’s daily functioning and activites – home work leisure
o DERMATOLOGY LIFE QUALITY INDEX TOOL - Stress, anxiety and/or depression
- Family history
clinical features of psoriasis
well demarcated erythematous scaly plaques
itchy, burning or painful lesions
extensor surfaces
auspitz sign
50% have ass nail changes - pitting onchylosis
- 5-8% suffer from associated psoriatic arthropathy - symmetrical polyarthritis, asymmetrical oligomonoarthritis, lone distal interphalangeal disease, psoriatic spondylosis, and arthritis mutilans (flexion deformity of distal interphalangeal joints)
how would a psoriatic lesion. be described as
symmetrical rash on extensor surfaces. Erythematous scaly plaques (slightly raised). Well defined. Scale is thick white/ silvery.
management for psoriasis
General Measures: Emollients, soap substitutes (aqueous cream)
1st Line: Topical therapies, corticosteroid, vitamin D analogues - Dovobet or ENSTILAR FOAM for chronic plaque psoriasis for 8-12 weeks
face/flexural/genitalia psoriasis - mild/moderate potent steroid ie eumovate 1/2 weeks
2nd Line: Phototherapy, acitretin, dimethy fumarate
3rd Line: Systemic therapy (methotrexate, cyclosporin, acitretin), biologicals
role of emollients
reduce scale
role of vit D analogues
Calcipotriol, Tacalcitol, and Calcitriol
Help regulate the immune system, slow the overgrowth of skin in psoriasis
Considered effective, safe and popular (don’t stain the skin, no strong odour) and can be used long-term
Can irritate sensitive skin areas e.g. the face & skin folds
Can cause hypercalcaemia so do not exceed the weekly limit
Not usually prescribed during pregnancy and breast feeding (manufacturer’s advice)
Can be combined with a steroid in a gel/ointment for short term use (risk of skin atrophy)
what is phototherapy
Fluorescent light bulbs imitating natural sunlight, using UVA and UVB wavelengths to reduce inflammation
3 times a week, usually 15-30 treatments
3 main types used
1) Broadband UVB (full UVB spectrum used): Psoriasis, Eczema (rarely used now)
2)Narrowband UVB (small part of UVB spectrum used, considered more effective): Severe Psoriasis & Eczema
3) PUVA (Psoralen+UVA): Psoriasis (if UVB not effective), Vitiligo, Cutaneous T-cell lymphoma
Psoralen: A chemical that increases the effect of UVA on skin, available as tablet or solution/lotion/gel
Most potent, reaches deeper layers of dermis, more side effects
side effects of phototherapy
Short-term: Redness and discomfort (sunburn) Dry and itchy skin Folliculitis Polymorphic light eruption (sunlight-induced rash) Cold sores Worsening of skin disease Psoralen: Nausea Long-term: Premature skin ageing, skin cancer
what is apremilast
Oral medication, inhibits an enzyme (Phosphodiesterase Inhibitor, PDE4); responsible for controlling the inflammatory process in the skin
Avoid live vaccines / getting pregnant whilst on it
Efficacy reduced by Cytochrome P450 inducers
Common SEs
GI upset (diarrhea, nausea, reduced appetite) Headache Insomnia Tiredness Muscle pain Respiratory infections
rare SEs
depression
weight loss
what is dimethyl fumarate (fumaric acid esters)
FAEs acts on the immune system
SEs: GI upset, headaches, flushing
Need to monitor LFTs, U&Es + urine dipstick for proteinuria, FBC (Rare: Progressive Multifocal Leukoencephalopathy)
More expensive (have to have failed other orals first)
Consider screening for HIV / hepatitis beforehand
Avoid pregnancy and breastfeeding whilst on it
use if biologics in psoriasis
Both Methotrexate and Ciclosporin have failed / are not tolerated / are contraindicated
The psoriasis has a large impact on physical, psychological or social functioning
The psoriasis is extensive or severely localised with functional impairment
Pre-treatment: Screen for TB, Hep B & C, HIV, VZV
Avoid live vaccines
1st line
Ustekinumab (IL-12 and IL-23 blocker)
Adalimumab (TNF alpha inhibitor) esp. if psoriatic arthropathy present)
Secukinumab (IL-17a inhibitor)
nail psoriasis features
- nail pitting
- Discolouration – ‘oil drop sign’ – orange yellow discolouration of the nail bed
- Subungal hyperkeratosis – hyperproliferation of the nail bed with accumulation of keratinocytes under the nail
- Onycholysis – detachment of the nail from the nail bed – bacteria and fungi are able to move in
- Complete nail dystrophy
what advice to give patients with psoriasis
give leaflet stop smoking drink alcohol within limits if overweight or obese - reduce weight assess for stress, anxiety and/or depression
complications of psoriasis
1) psychological and social effects
a. anxiety and depression
b. relationship difficulties
c. limitation of activities – swimming and work
2) physical effects
a. erythrodermic psoriasis – life threatening due to its impact on temperature regulation, haemodynamics, intestinal absorption, and protein and water metabolism.
b. Generalised pustular psoriasis – life-threatening and can cause fever, malaise, tachycardia, weight loss and hypothermia
causes of erythrodermic psoriasis
- Infections
- Low calcium
- Withdrawal of oral corticosteroids (prednisone)
- Withdrawal of excessive use of strong topical corticosteroids
- Strong coal tar preparations
- Certain medications including lithium, antimalarials and interleukin II
- Excessive alcohol consumption
complications of erythrodermic psoriasis
- Dehydration – reduction in the barrier function of the skin increases transepidermal water loss
- Malabsorption – enteropathy causes changes in intestinal absorption
- Heart failure – increase blood flow to skin, blood volume and cardiac output
- Infection
- Hypothermia – increased heat loss from the body surface
- Protein loss and malnutrition
- Oedema (swelling), particularly of lower legs
- Mild anaemia – iron deficiency due to skin losses from excess scaling, impaired absorption and utilisation of iron
- Death
management of erythrodermic psoriasis
- IV fluids and temp regulation
- Bland emollients and cooling wet dressings
- Bed rest
- Treatment of complications – Abx, diuretics and nutritional support
- Low dose methotrexate, ciclosporin or acitretin
- Maybe biologic agents
clinical features of erythroderma
Skin appears inflamed, oedematous and scaly
● Systemically unwell with lymphadenopathy and malaise
DD for mulitple torso lesions
viral or drug exanthema - not scaly
pityrisasis rosea - xmas tree pattern, herald patch scaling occurs at the edge of the plaques
guttate psoriasis
Ix for guttate psoriasis if complained about sore throat
AOT antistreptolysin titre
first line treatment for guttate psoriasis
emollients minimise adherent scale
coal tar preparations
vit D analogues
prognosis of guttate psoriasis
excellent
resolve within 6 months
what do you do if guttate psoriasis fails to settle
curse of phototherapy treatment helpful in sever or slow to resolve cases
what is the chance of developing chronic plaque psoriasis
most likely in patients who have had guttate psoriasis but by no means guranteed
what is ciclosporin
nephrotoxicity hepatotoxicity fluid retention hypertension hyperkalaemia hypertrichosis gingival hyperplasia tremor impaired glucose tolerance hyperlipidaemia increased susceptibility to severe infection
Interestingly for an immunosuppressant, ciclosporin is noted by the BNF to be ‘virtually non-myelotoxic’.
Indications following organ transplantation rheumatoid arthritis psoriasis (has a direct effect on keratinocytes as well as modulating T cell function) ulcerative colitis pure red cell aplasia
histology of psoriasis
irregular epidermal hyperplasia absence of the granular cell layer retention of nuclei in horny layer supracapillary thinning leukocyte infiltration
