Dermatology Flashcards
Layers of the skin from superficial to deep?
Epidermis
→ keratin layer
→ granular layer
→ prickle cell layer
→ basal cell layer
Dermoepidermal junction
Dermis
→ papillary dermis
→ reticular dermis
Outline the pathophysiology of acne?
- Androgens increase sebum production
- Sebum and keratin block the pilosebaceous unit leading to swelling and inflammation
- Colonisation of propionibacterium acnes leads to further inflammation
Features of acne vulgaris?
Mild = comedones
Moderate = comedones, pustules, papules
Severe = extensive inflammatory lesions, scarring
Management of acne vulgaris?
Depend on severity of symptoms:
→ benzoyl peroxide
→ topical retinoid
→ topical antibiotics
→ oral antibiotics or contraceptive (females)
→ oral retinoid
List some side effects of isotretinoin?
Teratogenic
Dry lips/mouth
Hair thinning
Low mood
Photosensitivity
Advice for prescribing Dianette for acne vulgaris?
Higher risk of VTE compared to other COCPs
Use for a maximum of 3 months
Advice for prescribing oral antibiotics for acne vulgaris?
Co-prescribe benzoyl peroxide or oral retinoid
Tetracycline is preferred
Use for a maximum of 3 months
Features and management of acne rosacea?
Facial flushing
Pustules, papules
Telangiectasia
Rhinophyma
Triggers e.g. UV, alcohol
Management = brimonidine (flushing), topical ivermectin, topical metronidazole, oral doxycycline
Topical steroid ladder?
Help Every Budding Dermatologist:
Mild = hydrocortisone
Moderate = eumovate (clobestasone butyrate)
Potent = betnovate (betamethasone)
Very potent = dermovate (clobetasol propionate)
Feature of atopic dermatitis (eczema)?
Dry, flaky, itchy skin on flexor surfaces
→ extensors/cheeks in babies
Management of atopic dermatitis (eczema)?
Emollient +/- topical steroid
Feature, cause and management of eczema herpeticum?
Monomorphic “punched out” lesions
Cause = HSV-1 or HSV-2 infection
Management = admission + IV aciclovir
Features, cause and management of impetigo?
Golden, crusted lesions around mouth
Cause = staphylococcus or streptococcus
Management = topical hydrogen peroxide or topical fusidic acid (limited), oral flucloxacillin (extensive)
School exclusion for children with impetigo?
48 hours after starting antibiotics
Types of contact dermatitis and cause?
Irritant = non-allergic reaction to chemical damage
Allergic = type IV hypersensitivity reaction to allergen
Investigation and management of contact dermatitis?
Investigation = patch testing
Management = emollient +/- topical steroid
Feature, cause and management of seborrhoeic dermatitis?
Dry, flaky, itchy skin on sebum-rich areas
Cause = malassezia furfur (yeast)
Management = topical ketoconazole
Feature and management of dermatitis herpetiformis?
Itchy, vesicular rash on extensor surfaces
Management = gluten-free diet, dapsone
Features of plaque psorasis?
Red, scaly plaques on extensors, scalp, trunk, buttocks
Nail changes e.g. pitting, onycholysis
Triggers of plaque psoriasis?
Skin trauma (Koebner phenomenon)
Beta-blockers, NSAIDs, lithium, anti-malarials
Management of plaque psoriasis?
1st line = emollient + topical steroid (OD) + topical vit D analogue (OD)
2nd line = emollient + topical vit D analogue (BD)
3rd line = emollient + topical steroid (BD)
N.B. dithranol (vit A analogue) and coal tar can also be used
Secondary care management of plaque psoriasis?
Phototherapy = narrowband UVB
Systemic therapy = methotrexate
Management of scalp psoriasis?
Topical steroid + softener e.g. salicylic acid
Features and management of guttate psoriasis?
“Tear drop” papules on trunk and limbs
2-4 weeks post-strep infection
Management = self-resolving
Features and management of lichen planus?
Itchy, purple, polygonal, papular rash
Wickham’s striae
Management = topical steroid
Drugs which can cause lichenoid eruption?
Beta-blockers
Gold
Thiazides
Anti-malarials
Features and management of lichen sclerosus?
Mostly elderly women
Genital itch
Atrophy
Scarring
Management = emollients +/- topical steroids
What is erythroderma and most common cause?
Erythema covering > 90% of body surface
Exacerbation of existing skin disease e.g. dermatitis
What is erythrasma and most common cause?
Pink/brown patches in damp areas e.g. groin
Overgrowth of corynebacterium
What is erythema multiforme and most common cause?
Type IV hypersensitivity reaction causing target lesions
HSV infection
What is erythema nodosum and most common cause?
Inflammation of subcut fat causing tender nodules
Group B strep infection
What is erythema ab igne and most common cause?
Reticulated pattern of erythema and hyperpigmentation
Infrared radiation e.g. hot water bottles