GP Derm Flashcards
What is the medical term for acne?
Acne vulgaris
What is acne caused by?
Chronic inflammation
+/- localised infection in pockets within the skin (pilosebaceous unit)
What is a pilosebaceous unit?
Tiny dimpes in the skin containing haor follicles + sebaceous glands
What do the sebaceous glands produce?
Natural skin oils + sebum (waxy substance)
How does acne develop?
Acne results from:
* Increased sebum production → trapping of keratin (dead skin cells) → blockage of the pilosebaceous unit
* → Swelling + inflammation in the pilosebaceous unit
What increases and decreases the production of sebum?
- Androgenic hormones = increase sebum production (hence why acne is exacerbated by puberty)
- Anti-androgenic hormonal contraception = decreases sebum production
What type of acne does bacteria play a major role in?
Propionibacterium acnes
(Bacteria colonises the skin → excessive bacteria growth = can exacerbate acne)
(Treatments = aim to reduce these bacteria)
Define macules
Flat marks on the skin
Define papules
Small lumps on the skin
Define pustules
Small lumps containing yellow pus
Define comedones
Skin coloured papules representing blocked pilosebaceous units
Define blackheads
Open comedones with black pigmentation in the centre
Define ice pick scars
Small indentations in the skin that remain after acne lesions heal
Define hypertrophic scars
Small lumps in the skin that remain after acne lesions heal
Define rolling scars
Irregular wave-like irregularities of the skin that remain after acne lesions heal
What are the aims of acne vulgaris treatment?
- Reduce symptoms
- Reduce risk of scarring
- Minimise the psychosocial impact
Name the options for the management for acne and what order is the stepwise fashion (based on severity + response to treatment)?
- No treatment (if mild)
- Topical benzoyl peroxide (↓ inflammation, unblock skin, toxic to P. acnes bacteria)
- Topical retinoids (chemicals related to vitamin A; ↓ sebum production)
- Topical antibiotics (clindamycin) + benzoyl peroxide (↓ antibiotic resistance)
- **Oral antibiotics (lymecycline) **
- Oral contraceptive pill (stabilse hormones + ↓ sebum production) (Dianette = most effective combined contraceptive pill)
- Oral retinoids (isotretinoin) (highly teratogenic)
What is an effective last-line option for severe acne?
Oral retinoids e.g. isotretinoin
* Prescribed by specialist after other methods fail
* Follow-up + reliable contraception
* ** = Highly teratogenic**
What is the most effective combined contraceptive pill for acne treatment?
Co-cyprindiol (Dianette)
= Most effective due to its anti-androgenic effects
= High thromboembolism risk → discontinued after acne is controlled (not prescribed long-term)
How are oral retinoids (isotretinoin) (e.g. Roaccutane) effective?
- Reduce sebum production
- Reduce inflammation
- Reduce bacterial growth
Name a side effect of oral isotretinoin?
- Dry skin and lips
- Photosensitivity of the skin to sunlight
- Depression, anxiety, aggression and suicidal ideation (patients should be screened for mental health issues prior to starting treatment)
- Rarely Stevens-Johnson syndrome and toxic epidermal necrolysis
What is psoriasis
A chronic autoimmune condition that causes recurrent symptoms of psoriatic skin lesions
Is psoriasis genetic?
Clear genetic component - but no clear genetic inheritance
Approx. 1/3 patients have a first degree relative with psoriasis
Symptoms start in childhood in a 1/3 of patients
In basic terms, how does psoriasis present?
Patches of psoriasis are dry, falky, scaly, faintly erythematous skin lesions in raised + rough plaques - commonly over extensor surfaces of the elbows + knees + scalp
Simple pathophysiology of psoriasis
Skin changes = caused by the rapid generation of new skin cells → resulting in an abnormal buildup thickening of skin in those areas
What are the types of psoriasis?
- Plaque psoriasis
- Guttate psoriasis
- Pustular psoriasis
- Erythrodermic psoriasis
How does plaque psoriasis present?
- Thickened erythematous plaques with silver scales
- Commonly seen on the extensor surfaces + scalp
- Plaques are 1-10cm diameter
(Most common form of psoriasis in adults)
How guttate psoriasis present? And how in?
Guttate psoriasis = 2nd most common form of psoriasis, commonly presents in children
- Many small raised papules across the trunk + limbs
- Papules = mildy erythematous + can be slightly scaly
- Over time, the papules → turn into plaques
- Guttate psoriasis = often triggered by a streptococcal infection, stress or medications
- Often resolves spontaneously within 3-4 months
What is guttate psoriasis often triggered by?
Streptococcal throat infection
What is pustular psoriasis?
- Rare severe form of psoriasis
- Pustules = form under areas of erythematous skin
- The pus in these areas = not infectious
- Can be systemically unwell
- Treated as medical emergency - require hospital admission
What is erytherodermic psoriasis?
- Rare severe form of psoriasis
- Extensive erythematous inflamed areas - covering most of the surface of the skin
- The skin = comes away in large pathches (exfoliation) → resulting in raw exposed areas
- Medical emergency - requires hopsital admission
What form of psoriasis is most common in children, that is often triggered by a throat infection?
Guttate psoriasis
How might psoriasis present differently in children from adults?
In children - psoriasis plaques may be smaller, softer and less prominent
What are the 3 specific signs suggestive of psoriasis?
- Auspitz sign → small points of bleeding when plaques are scraped off
- Koebner phenomenon → development of psoriatic lesions to areas of skin affectsed by trauma
- Residual pigmentation of the skin after lesions resolve
How can a diagnosis of psoriasis be made?
Clinical diagnosis - based on the appearance of the lesions
What is the management for psoriasis?
- **Topical steroids **
- Topical vitamin D analogues (calcipotriol)
- Topical dithranol
- Topical calcineurin inhibitors (tacrolimus) are usually only used in adults
- Phototherapy with narrow band ultraviolet B light is particularly useful in extensive guttate psoriasis
- Severe + difficult to treat:** Methotrexate, cyclosporine, retinoids, biologic medications**
What are the two commonly used products prescribed for psoriasis?
(They contain a potent steroid + vitamin D analogue)
- Dovobet
- Enstilar
What are some associations of psoriasis?
- Nail psoriasis (nail changes that occur in psoriasis) → nail pitting, thickening, discolouration, ridging, onycholysis (separation of the nail from bed)
- Psoriatic arthritis (10-20%) → usually occurs within 10 years of skin changes - middle age
- Psychosocial → mood, self-esteem, social acceptance → depression + anxiety
- Other co-morbidities that increase the risk of cardiovascular disease are associated with psoriasis, particularly obesity, hyperlipidaemia, hypertension and type 2 diabetes.
What is impetigo?
A superficial bacterial skin infection - usually caused by a staphylococcus skin infection
Occurs when bacteria enter via a break in the skin
What are the 2 common causative organisms of impetigo?
- Staphylococcus aureus (most common)
- Streptococcus pyogenes