Dermatology Flashcards
Covers chronic skin conditions and common ones: Psoriasis Acne vulgaris Rosacea Eczema Seborrhoeic dermatitis contact dermatitis Skin cancers- BCC, SCC, Melanoma vs premalignant conditions (e.g. bowens, kerathoacanthoma etc, benign naevus) vitiligo
Define psoriasis
Psoriasis is a chronic autoimmune & inflammatory skin condition characterised by well demarcated red scaly plaques.
Quick overview of the pathophysiology of psoriasis?
autoimmune and T cell mediated disease, inflammatory cells produce cytokines, this leads to infiltration of other inflammatory cells leading to redness, and keratinocyte proliferation - leading to scale as as stratum corenum is shed from the skin.
Risk factors for psoriasis?
- genetics
- caucasian
- equal between M & F
- infections - streptococcal & guttate psoriasis
- hormonal changes (puberty and menopause) & post partum period (often improves during pregnancy)
- change of medications - beta blockers, lithium, chloroquine and ACEi worsen, withdrawal of steroids
- trauma/ sunburn - koebner phenomenon
- smoking and alcohol
- HIV
- psychological stress
relieving factor for psoriasis?
sunlight improves symptoms (psoraisis better in summer vs winter)
In a small number of patients it can be an exacerbating factor
Types of psoriasis?
5 main types:
1) chronic plaque psoriasis –> commonest type, symmetrical plaques on extensor surfaces of the limbs - knees and elbows, scalp and lower back.
2) flexural psoriasis –> smooth red plaques without scale in flexures and skin folds
3) guttate psoriasis –> multiple small tear drop shaped red plaques on the trunk after streptococcal infection in young adults
4) pustular psoriasis –> multiple petechiae and pustules on the palms and soles
5) generalised erythrodermic psoriasis –> rare but serious form characterised by redness and systemic illness
Key features of a history of psoriasis?
symptoms
other key features on the history?
Symptoms of psoriasis:
- pruritic lesion
- typically erythematous, circumscribed scaly plaque
often elbows, knees, extensors, scalp, less commonly nails, ears, umbilical region
pain or burning sensation around lesion
joint pain and stiffness in psoriatic arthritis (affects 20%)
family history common
check medications - lithium, beta blockers, ACEi or steroid cessation
Type of psoriasis with this sign?

Nail pitting is common with psoriasis and psoriatic arthritis
What is the type of psoriasis?

Plaque psoriasis affecting the knee
Type of psoriasis?

Guttate psoriasis
widespread erythematous fine scaly papules with a water drop appearance often on trunk arms and legs. Often erupts after URTI
Type of psoriasis?

Pustular psoriasis - acute generalised pustular psoriasis, rare severe and urgent, affects palms and soles and is chronic
What type of psoriasis is this?

Eythrodermic psoriasis with generalised erythema and fine scaling, often associated with pain, irritation and sometimes severe itching
It is a rare but severe form of psoriasis which can occur acutely as first presentation or may evolve from chronic psoriasis. Widespread inflammation of the skin leads to significant fluid loss, resulting in dehydration, electrolyte loss, peripheral oedema and rarely hypothermia & HF. It requires hospital admission for inpatient mx.
Clinical examination features of psoriasis?
Psoriatic lesions are:
Well demarcated
erythematous
plaques
assocaited with overlying scale
auspitz’s sign - if you remove the scale the lesion bleeds
koebner phenomenon- new lesions at sites of damage
on extensor surfaces mostly, elbows, knees and scalp
if on flexural surfaces may be shiny and moist
usually discrete by may coalesce
nail changes - pitting, onycholysis, yellowing and ringing (associated with more severe disease if nail changes are present)
How do we diagnose psoriasis?
usually no investigations are necessary it is a clinical diagnosis.
Psoriasis area and severity index PASI is a clinical tool to assess the severity.
You can order a skin biopsy where there is doubt in diagnosis.
What are some of the associated conditions with psoriasis?
- Psoriatic arthritis –> chronic seronegative inflammatory arthritis, estimated one third develop psoriatic arthritis
- onset normally follows skin disease by 5-10 yrs but occasionally arthritis develops before skin changes
- psoriatic nail changes occur in 90%
- Other conditions associated include –> IBD, metabolic syndrome, CV disease, other autoimmuen conditions, eye pathologies including uveitis, blepharitis and conjunctivitis.
Management of chronic plaque psoriasis?
- Conservatively –> avoid exacerbating factors, smoking cessation, reduce alcohol consumption and maintain optimal weight
- Medical:
- topical therapy first line - they reduce itch and clear plaques
- regular emollient to reduce scale and itch
- potent corticosteroid applied OD plus vitamin D analogue applied OD (calcipotriol)
- applied separately one in the morning and one in the evening
- up to 4 weeks as initial tx
- 2nd line if there is no improvement
- vitamin D analogue twice daily
- 3rd line if no improvement
- potent corticosteroid twice daily or coal tar prep
Secondary care:
- phototherapy UVB 3x/ wk
- adverse effects include ageing and SCC
Systemic therapy
- oral methotrexate used 1st line especially if assocaited joint disease
- other immunosuppressants e.g ciclosporin, retinoids, biologics
Complications of psoriasis?
chronic plaque psoriasis is a lifelong condition and is frequently resistant to treatment.
Therefore it is associated with significant psychosocial burden, screen regularly for anxiety and depression.
Systemic upset e.g. erythrodermic psoriasis and generalised pustular psoriasis are lifethreatening and severe.
medication used to tx psoriasis often has troubling or severe side effects:
E.g. steroids with skin atrophy, striae and rebound symtoms, aim for 4 week break before starting another course of topical corticosteroid
Vitamin D analogues e.g. calcipotriol can be used long term, reduce scale and plaques not erythema but avoid in pregnancy
what are the differentials for a scaly rash?
- Pityriasis rosea
- Tinea
- Seborrhoeic dermatitis
- discoid eczema
- bowen’s disease
- discoid lupus
- scabies
What are the potencies of topical steroids?
What are important points to communicate to patients with steroids?
Topical corticosteroids are available in 4 different potencies - “Help Every Budding Dermatologist”
Hydrocortisone (mild)
Eumovate (moderate)
Betnovate (potent)
Dermovate (very potent)
- Potent topical corticosteroids should not be used on the face or genitals
- very potent topical steroids should not be used in primary care only by dermatologists
Define acne vulgaris
common condition in adolescence resulting from inflammation of the pilosebaceous unit, leads to the development of comedones, pustules and papules.
cause of acne vulgaris
- Due to increased sebum production
- & increased androgenic hormones at adolescence that cause hyperplasia of the sebaceous glands
- bacterial colonisation ( P acnes) leading to inflammation of the pilosebaceous unit.
- hyperactive immune response
risk factors of acne vulgaris
- Typically related to natural hormonal shifts that occur during puberty or excess androgens - PCOS, congenital adrenal hyperplasia, exogenous steroid
- exacerbated by steroids & antiepileptics
- worsened by topical skin products e.g. cosemetics and shaving products
Clinical features of acne
non inflammatory comedones - closed and open comedones. Closed comedones (whiteheads) are plugged follicles, open comedones (black heads)
inflammatory papules, pustules, nodules and cysts.
Papules and pustules are small raised lesions < 5mm
Nodules and cysts are deeper larger lesions > 5mm
often located in face chest and back with many pilosebaceous units.
Chronic disease may lead to scarring due to healing of lesions.
Definitions of derm terminology with acne:
Comedone
Papule
Pustule
Comedone = dilated sebaceous follicle in the skin (pore) which can be open (blackhead) or closed (whitehead) due to accumulation of bacterial and cellular debris
Papule = solid raised lesion less than 0.5cm in diameter
Pustule = a lesion less than 0.5cm in diameter that contains pus
Definitions of derm terminology in acne:
Nodule
Cyst
Nodule = solid raised lesion less than 0.5cm in diameter but with a deeper component
Cyst = thin walled closed capsule or sac containing fluid



















