Dermatology Flashcards
Pathophysiology eczema
Defects in skin barrier
Entrance for irritants, microbes and allergens
Can stimulate an immune response
Inflammation and associated symptoms
Distribution of eczema
Face and trunk in infants
In younger children extensor surfaces
In older children flexor surfaces and creases of face and neck
Management of eczema
Avoid irritants
Emollients
Topical steroids
Wet wraps and oral cyclosporine in severe cases
Severe eczema management
Zinc-impregnated bandages Topical tacrolimus Phototherapy Systemic immunosuppressants Oral corticosteroids Methotrexate Azathioprine
Management of eczema flares
Thicker emollients
Wet wraps
Treating infections
Eczema trigger
Cold air Dietary products Washing powders Cleaning products Emotional event or stresses
Thin emollients
E45 Diprobase Oliatum cream Aveeno cream Cetraben cream Epaderm cream
Thick, greasy emollients
50:50 ointment Hydromol ointment Diprobase ointment Cetraben ointment Epaderm ointment
Side effects of topical steroids
Thinning of skin, more prone to flares, bruising, tearing, stretch marks, enlarged blood vessels (telangiectasia)
Mild steroids topical
Hydrocortisone
0.5-2.5%
Moderate topical steroids
Betamethasone valerate 0.025% (Betnovate)
Clobetasone butyrate (Eumovate)
Potent topical steroids
Fluticasone propionate 0.05% (Cutivate)
Betamethasone valerate 0.1% (Betnovate)
Very potent topical steroids
Clobetasol propionate
0.05% (Dermovate)
Eczema herpeticum causes
HSV 1 (more common) or 2 Varicella zoster virus Severe primary infection of skin Seen in children with atopic eczema Rapidly progressing painful rash
Presentation of eczema herpeticum
Widespread, painful, vesicular rash Rapidly progressing rash Monomorphic punched-out erosions (1-3mm) Fever, lethargy, irritability, reduced oral intake Lymphadenopathy
Management of eczema herpeticum
Viral swabs of vesicles
IV aciclovir
Complications of eczema herpeticum
Life-threatening
Bacterial superinfection
Psoriasis presentation
Dry, flaky, scaly, rough Faintly erythematous skin lesion Raised plaques Over extensor surfaces Elbows, knees, scalp
Rapid generation of new skin cells, abnormal buildup and thickening of skin in those areas
Plaque psoriasis
Thickened erythematous plaques with silver scales
Commonly seen on the extensor surfaces and scalp
1cm-10cm in diameter
Most common form of psoriasis in adults
Guttate psoriasis features
More common in children and adolescents
Precipitated by a streptococcal infection 2-4weeks prior to lesions appearing
Tear drop papules on trunk and limbs
Turn into plaques over time
Guttate psoriasis management
Resolves within 3-4months
Phototherapy
Tonsillectomy
Topical agents
Pustular psoriasis
Systemically unwell
Pustules form under areas of skin
Immediate admission to hospital
Erythrodermic psoriasis
Extensive erythematous inflamed areas covering most of the surface area of the skin
Skin comes away in large patches
Raw exposed areas
Medical emergency requiring admission
Specific signs associated with psoriasis
Auspitz sign: small points of bleeding when plaques are scraped off
Koebener phenomenon: development of psoriatic lesions in areas of skin affected by trauma
Residual pigmentation of skin after lesions resolve
Management of psoriasis
Psychosocial support Topical steroids Topical vitD analogue (calcipotriol) Topical dithranol Phototherapy with narrow band UV B light
Specialist: methotrexate, cyclosporine, retinoids, biologic medications
Complications/ associations of psoriasis
Nail psoriasis: nail pitting, thickening, discolouration, ridging, onycholysis
Psoriatic arthritis
Psychosocial
CVD: obesity, hyperlipidaemia, HTN, T2DM
Pathophysiology of acne vulgaris
Chronic inflammation and swelling in pilosebaceous unit—>form comedones
From Increased production of sebum, trapping of keratin, blockage of pilosebaceous unit
Androgenic hormones increase production of sebum
Propionibacterium acnes bacteria
Features of acne vulgaris
Comedones due to a dilated sebaceous follicle: open top is whitehead, closed top is blackhead
Follicle bursts releasing irritants: papules, pustules
Excessive inflammatory response: nodules, cysts
Scarring: ice pick scars, hypertrophic scars, rolling scars
Drug-induced acne is monomorphic
Acne fulminans: systemic upset, hospital admission, oral steroids
Classification of acne vulgaris
Mild: open and closed comedones with/without sparse inflammatory lesions
Moderate: widespread non-inflammatory lesions and numerous papules and pustules
Severe acne: extensive inflammatory lesions, nodules, pitting, scarring
Management of acne vulgaris
Single topical therapy: topical retinoids, benzoyl peroxide
Topical combination therapy: topical antibiotics (clindamycin), benzoyl peroxide, topical retinoid
Oral antibiotics or COCP
Oral isoretinoin
Topical benzoyl peroxide acne
Reduces inflammation
Helps unblock skin
Toxic to P.acnes bacteria
Topical retinoids acne
Chemicals related to vitamin A
Slows production of sebum
Oral antibiotics acne
Tetracyclines: lymecycline
Contraindicated in pregnancy/ breast feeding/ <12
Erythromycin used in pregnant
Use for 3 months maximum
Always prescribe with topical retinoid or benzoyl peroxide to prevent resistance
Complications of long-term ax use: gram-negative folliculitis, treat with high dose oral trimethoprim
COCP acne
Dianette (co-cyrindiol)
Increases VTE risk
Only give for 3 months, second-line
Oral isoretinoin acne
Last-line options
Pregnancy is a contraindication,Need contraception
Roaccutane
Side effects of oral isoretinoin
Dry skin and lips
Photosensitivity of skin to sunlight
Depression, anxiety, aggression, suicidal ideation
Stevens-Johnson syndrome and toxic epidermal necrolysis
Human papilloma virus
Infects keratinocytes of skin and mucous membranes
Carcinogenic
6&11 genital wards
16&18 cancer, cervical cancer
HPV vaccination
12-13year olds in year8 will be offered 2 doses
Daughter may receive vaccine against parental wishes
Protects against 6,11,16,18
Management of genital warts
HPV
First line
Multiple, non-keratinised warts: topical podophyllum
Solitary, keratinised warts: cryotherapy
Second line:
Imiquimod topical cream
Impetigo
Superficial bacterial infection
Staphylococcal aureus bacteria or strep pyogenes
Complication of eczema, scabies or insect bites
Common in children in warm weather
Contagious, need school exclusion until lesions are crusted and healed or 48hours after antibiotic treatment
Impetigo features
Face, flexures and limbs not covered by clothing
Golden crust, around mouth
Impetigo spread
Direct contact with discharged from the scabs of an infected person
Spreads by scratching to other sites
Incubation 4-10days
Non-bullous impetigo
Typically occurs around nose or mouth
Systemically well
Golders crust from dried exudate
Management of non-bulbous impetigo
Antiseptic cream (hydrogen peroxide 1%) first line
Second line topical antibiotic creams:
Topical fusidic acid
Topical mupirocin if resistant
Extensive disease:
Oral flucloxacillin
Oral erythromycin is penicillin-allergic
School exclusion:
Until lesions are crusted and healed
Until 48 hours after ax treatment
Bullous impetigo
Staphylococcus aureus infection
Epidermolytic toxins that break down proteins that hold skin cells together
Vesicles-> exudate
More common in <2s and neonates
Systemic symptoms
If severe: staphylococcal scalded skin syndrome
Swabs of vesicles
Treatment of bullous impetigo
Flucloxacillin
Oral/IV
Complications of impetigo
Cellulitis Sepsis Scarring Post-streptococcal glomerulonephritis Staphylococcal scalded skin syndrome Scarlet fever
Staphylococcal scalded skin syndrome
Caused by staph aureus which produces epidermolytic toxin (protease)
Breaks down proteins that hold skin cells together
Usually affects <5 years old
Older children and adults usually have immunity
Presentation of staphylococcal scalded skin syndrome
Patches of erythema on skin
Skin looks thin and wrinkled
Formation of fluid filled blisters called bullae, which burst and leave sore, erythematous skin below
Similar appearance to burn or scald
Nikolysky sign: gentle rubbing of skin causes it to peel away
Systemic symptoms: fever, irritability, lethargy, dehydration
Management of staphylococcal scalded skin syndrome
Admission and treatment with IV ax
Fluid and electrolyte balance as patients are prone to dehydration
Children usually make a full recovery without scarring with adequately treated
Steven-Johnson syndrome and toxic epidermal necrolysis
Disproportional immune response Epidermal necrolysis I Blistering and shedding of top layer of skin SJS <10% surface area affected TEN: >10% surface area affected HLA genetic
Causes of Steven-Johnson syndrome and toxic epidermal necrolysis
Medications: Anti-epileptic Antibiotics Allopurinol NSAIDs
Infections: Herpes simplex Mycoplasma pneumoniae CMV HIV
Presentation of Steven Johnson syndrome
Maculopapular rash with target lesions
Develop into vesicles or bullae
Mucosal involvement
Fever, arthralgia
Purple/red rash that spreads and blisters
Skin sheds
Pain, erythema, blistering and shedding lips and mucous membranes
Eyes inflamed and ulcerated
Urinary tract, lungs and internal organs involvement
Toxic epidermal necrolysis presentation
Systemically unwell, pyrexia, tachycardia
Positive Nikolysky sign: epidermal separates with mild lateral pressure
Purple/red rash that spreads and blisters
Skin sheds
Pain, erythema, blistering and shedding lips and mucous membranes
Eyes inflamed and ulcerated
Urinary tract, lungs and internal organs involvement
Management of SJS and TEN
Medical emergencies Nutritional Antiseptics Analgesia Ophthalmology input Steroids Immunosuppressants: cyclosporine and cyclophosphamide Immunoglobulins
Complications of SJS TEN
Secondary infection
Permanent skin damage
Visual complications: scarring and blindness
Two types of contact dermatitis
Irritant contact dermatitis
Allergic contact dermatitis
Caused by cement
Irritant contact dermatitis
Non-allergic
Due to weak acids or alkalis
Often seen on the hands
Erythema is typical, crusting and vesicles are rare
Allergic contact dermatitis
TY4 hypersensitivity reaction
Often seen on head following hair dyes
Presents as acute weeping eczema which predominantly affects the margins of the hairline
Topical treatment with potent steroids
Viral exanthem
Eruptive widespread rash First disease: measles Second disease: scarlet fever Third disease: rubella Fourth disease: Duke’s disease Fifth disease: parvovirus B19 Sixth disease: roseola infantum
Measles exposure
Symptoms start 10-12days after exposure
Respiratory droplet spread
Measles virus
Face rash 3-5days after fever
Measles features
Fever, coryzal symptoms, conjunctivitis
Koplik spots 2 days after fever
Rash behind ears ten to rest of body, erythematous macular rash with flat lesions
Measles management
Self resolving after 7-10days
Isolate children until 4 days after symptoms have resolved
Notifiable disease
Complications of measles
Pneumonia Diarrhoea Dehydration Encephalitis Meningitis Hearing loss Vision loss Death
Scarlet fever transmission and cause
Cause: Group A streptococcus (tonsilitis)
Step pyogenes exotoxin
Scarlet fever features
Red-pink blotchy macular rash Sandpaper skin that starts on trunk and spreads outwards Red, flushed cheeks Fever Lethargy Flushed face Sore throat Strawberry tongue Cervical lymphadenopathy
Scarlet fever management
Phenoxymethylpenicillin (Penicillin V) 10 days
Notifiable disease
Keep children off school until 24hours of antibiotics
Conditions associated with group A strep infections
Scarlet fever
Post-streptococcal glomerulonephritis
Acute rheumatic fever
Rubella transmission
Rubella virus
Highly contagious
Spread by resp droplets
Symptoms start 2 weeks after exposure
Rubella features
Symptoms start 2 weeks after exposure
Milder erythematous macular rash compared with measles
Rash starts on face and spreads to rest of body
Lasts 3 days
Mild fever, joint pain, sore throat
Lymphadenopathy behind ears and back of neck
Rubella management
Supportive and self-limiting
Notifiable disease
Children stay off school for 5 days after rash appears
Children should avoid pregnant women
Complications of rubella
Thrombocytopenia
Encephalitis
Dangerous in pregnancy-> congenital rubella syndrome (deafness, blindness, congenital heart disease)
Dukes disease
Non-specific viral rashes
Parvovirus B19
Fifth disease, slapped cheek syndrome, erythema infectiosum
Symptoms of parvovirus B19
Mild fever, coryza, non-specific viral symptoms (muscle aches and lethargy)
After 2-5 days rash appears rapidly, diffuse bright red rash on both cheeks
Reticular (net-like) mildly erythematous rash affecting trunk and limbs, raised and itchy
Management of parvovirus B19
Self-limiting
Symptoms fade over 1-2weeks
Supportive management, fluids, simple analgesia
Infectious prior to rash forming, once rash formed no longer infectious
Patients at risk of complications of parvovirus infection
Immunocompromised patients Pregnant women Sickle cell anaemia Thalassaemia Hereditary spherocytosis Haemolytic anaemia
These patients need serology testing to confirm diagnosis
Check FBC, reticulocyte count for aplastic anaemia
Complications of parvovirus infection
Aplastic anaemia
Encephalitis or meningits
Pregnancy complications including fetal death
Rarely hepatitis, myocarditis, nephritis
Roseola infantum
Sixth disease
Human herpesvirus6
Human herpesvirus7
Roseola infantum presentation
Typical pattern of illness
Presents 1-2weeks after infection with a high fever (up to 40degrees), lasts 3-5 days then disappears suddenly
Coryzal symptoms, sore throat, swollen lymph nodes during the illness
Fever settles and rash appears for 1-2days
Mild erythematous macular rash across the arms, legs, trunk and face is not itchy
Management of roseola infantum
Children make full recovery within a week and don’t generally need to be kept off nursery if they are well enough to attend
Complication of roseola infantum
Febrile convulsions: high temperatures
Immunocompromised patients at risk of myocarditis, thrombocytopenia, Guillian-Barre syndrome
Erythema multiforme
Causes and associations
Erythematous rash caused by hypersensitivity reaction
Causes: viral infections, medications
Associations: herpes simplex virus, mycoplasma pneumoniae
Erythema multiforme presentation
Widespread, itchy, erythematous rash
Target lesions
Sore mouth; stomatitis
Symptoms come on abruptly over a few days, mild fever, stomatitis, muscle and joint aches, headaches, general flu-like symptoms
Erythema multiforme management
Diagnosis based on appearance of rash Identify underlying cause CXR for mycoplasma pneumoniae Self resolves 1-4qeeks Severe: IV fluids, analgesia
Pathophysiology of urticaria
Caused by release of histamine and mast cells
Allergic reaction in acute urticaria
Autoimmune reaction in chronic idiopathic urticaria
Causes of acute urticaria
Allergies to food, medications or animals
Contact with chemicals, latex or stinging nettles
Medications
Viral infections
Insect bites
Dermatographism
Chronic urticaria types
Chronic idiopathic urticaria
Chronic inducible urticaria
Autoimmune urticaria
Chronic idiopathic urticaria
Recurrent episodes of chronic urticaria without a clear underlying cause or trigger
Chronic inducible urticaria
Episodes of chronic urticaria that can be induced by certain triggers
Sunlight, temperature changes, exercise, strong emotions, hot or cold weather, pressure (dermatographism)
Autoimmune urticaria
Chronic urticaria associated with a chronic autoimmune condition
Management of urticaria
Fexofenadine (antihistamine)
Short course of oral steroids for severe flares
Management of problematic urticaria
Anti-leukotrienes (montelukast)
Omalizumab (IgE)
Cyclosporin
Chickenpox presentation
Widespread, erythematous, raised, vesicular (fluid-filled) blistering lesions
Rash starts on trunk/face and spreads outwards
Whole body by day 2-5
Scab over and stop being contagious
Fever
Itch
Malaise and fatigue
Chickenpox infectivity
Highly contagious
Infected droplets from a cough or sneeze
Patients become symptomatic 10days to 3weeks after exposure
Stop bring infectious once lesions have crusted over
Chickenpox complications
Bacterial superinfection Dehydration Conjunctival lesion Pneumonia Encephalitis (ataxia) Shingles
Antenatal and neonatal chickenpox
If not immune, give pregnant women varicella zoster immunoglobulin
In pregnancy, congenital varicella syndrome in baby if <28weeks gestation
Infection around delivery time: management with varicella zoster immunoglobulins and aciclovir
Management of chickenpox
Aciclovir: in immunocompromised, >14 presenting in <24hours, neonates, those at risk of complications
Encephalitis: need admission
Itching: calamine lotion and chlorphenamine (antihistamine)
Off school and avoid pregnant women until lesions have crusted over, 5 days after rash first appears
Hand foot and mouth disease presentation
Coxsackie A virus
3-5 days incubation
URT symptoms: tiredness, sore throat, dry cough, raised temperature
Small mouth ulcers after 1-2 days
Then blistering red spots around body, hands feet mouth (painful)
Management hand foot mouth disease
Supportive
Resolves 7-10days
Avoid sharing towels and bedding, washing hands and careful handling of dirty nappies
Complications of hand, foot and mouth disease
Dehydration
Bacterial superinfection
Encephalitis
Molluscum contagiosum features
Small, flesh coloured papules
Central dimple
Crops of multiple lesions in an area
Spread through contact, sharing bedsheets
Molluscum contagiousum management
Resolves spontaneously
Can take up to 18months to resolve
Once resolved skin returns to normal
Avoid scratching or picking at lesions
Management molluscum contagiousum
Avoid sharing towels or close contact with lesions
If bacterial superinfection: superficial fusidic acid or oral flucloxacillin
Immunocompromised patients: specialist referral, topical potassium hydroxide, benzoyl peroxide, podophyllotoxin, imiquimod, retinoin. Surgical removal and cryotherapy
Pityriasis rosea presentation
Prodromal symptoms prior to rash developing
Headache, tiredness, loss of appetite, flu-like symptoms
Herald patch (faint red, scaly, oval) >2cm diameter on torso
2days later rest of rash appears
Christmas tree rash on torso
Lesions grey or lighter if darker skin
Itch, pyrexia, headache, lethargy
Pityriasis rosea disease course
Rash resolves without treatment within 3 months
Skin discolouration resovled in another few months
Pityriasis rosea disease course
Patient education and reassurance
Not contagious, can resume normal activities
Symptomatic treatment if bothered by itching
Emollients, topical steroids, sedating antihistamines at night to help sleep
Scabies
Sarcoptes scabiei mites burrow under skin and cause infection and intense itching
Lay eggs in skin, further infection and symptoms
8 weeks for symptoms/rash to appear after initial infection
Scabies presentation
Itchy small red spots
Track marks where mites have burrowed
Location of rash is between finger webs, can spread to whole body
Scabies management
Permethrin cream If difficult to treat: oral ivermectin Treat household contacts Hot wash Itching 4 weeks after infecton resolved, crotamitron cream, chlorphenamine at night
Crusted scabies
Norwegian scabies Infection in immunocompromised patients Scaly plaques No itch Oral ivermectin and admission/isolation
Head lice
Pediculus humanus capitis parasites
Cause infestations of scalp
Itchy sca,lp
Head lice management
Dimeticone 4% lotion to hair left overnight then washed off, 7 day
Bug buster kit, special combs
DD non-blanching rash
Meningococcal septicaemia HSP Idiopathic thrombocytopenic purpura Acute leukaemia Haemolytic uraemic syndrome: oliguria, presents in child with recent gastroenteritis Mechanical: strong coughing, SVC obstruction, vomiting, breath holding Viral illness: influenza, enterovirus Traumatic
Erythema nodosum
Red lumps across shins
Inflammation of subcutaneous fat on shins (panniculitis)
Hypersensitivity reaction
Erythema nodosum hypersensitivity reaction causes
Streptococcal throat infections Gastroenteritis Mycoplasma pneumoniae Tuberculosis Pregnancy COCP
Erythema nodosum chronci disease associations
IBD
Sarcoidosis
Lymphoma
Leukaemia
Erythema nodosum investigations
Inflammatory markers
Throat swab for strep infection
CXR: mycoplasma, TB, sarcoidosis, lymphomas
Stool microscopy and culture: campylobacter, salmonella
Faecal calprotectin for IBD
Management of erythema nodosum
Rest and analgesia
Conservative management
Steroids for inflammation
Most cases will fully resolve in 6 weeks
Seborrhoeic dermatitis
Inflammatory skin condition that affects the sebaceous glands
Scalp, nasolabial folds and eyebrows
Causes erythema, dermatitis and dry crusted skin
Cradle cap
Malassezia yeast
Infantile seborrheic dermatitis
Cradle cap, crusted flaky scalp
Self-limiting condition and resolves by 4 months of age, can last until 12 months
First line: oil, brush scalp, white petroleum jelly overnight,
Second line: antifungal clotrimazole, miconazole for up to 4 weeks
Seborrheic dermatitis of the scalp
Dandruff
Dense oily scaly brown crusting
More common in adolescents and adults
First line: ketoconazole shampoo, topical steroids if severe itching
Seborrheic dermatitis of face and body
Red, flaky, crusted, itchy skin
Commonly affects eyelids, nasolabial folds, ears, upper chest, back
First line treatment: clotrimazole or miconazole antifungal cream, hydrocortisone 1% for localised inflamed areas
Tinea capitis
Ringworms affecting scalp
More common in children
Tinea pedis
Ringworm affected feet
Athletes foot
White or red, flaky, cracked, itchy patches between the toes
Skin may split and bleed
Tinea cruris
Ringworm of groin
Tinea corporis
Ringworm on body
Onychomycosis
Fungal nail infection
Thickened, discoloured and deformed nails
Name of fungus causing ringworm
Trichophyton
Ringworm presentation
Itchy rash
Erythematous, scaly, well demarcated
Management of ringworm
Clotrimazole and miconazole antifungal creams
Ketoconazole shampoo for tinea capitis
Oral antifungal: fluclonazole, griseofulvin, itraconazole
Fungal nail infections: amorolfine nail lacquer for 6-12months, oral terbinafine after checking LFTs
Daktacort: hydrocortisone 1% and miconazole 2%
Ringworm advice
Wear loose breathable clothing
Keep affected areas clean and dry
Avoid sharing towels, clothes or bedding
Use a separate towel for feet with tinea pedis
Avoid scratching and spreading to other areas
Wear clean dry socks every day
Tinea incognito
Fungal skin infection that results from the use of steroids to treat an initial fungal infction
Steroids slow down immune response, allowing fungus to grow
Less dermarcated border and less scales
Nappy rash
Contact dermatitis Friction between skin and nappy Contact with urine and faeces Common 9-12months of age Added fungal (candida), bacteria (staph/strep) infection
Risk factors for nappy rash
Delayed changing of nappies
Irritant soap products and vigorous cleaning
Poorly absorbent nappies
Diarrhoea
Oral antibiotics predispose to candida infection
Pre-term infants
Nappy rash presentation
Sore, red, inflamed skin in nappy area
Skin creases spared
Red papules
Erosions and ulceration eventually
More likely candida than nappy rash
Rash extending into skin folds Larger red macules Well-dermarcated scaly border Circular pattern to the rash spreading outwards, similar to ringworm Satellite lesions Oral thrush
Management of nappy rash
Switch to highly absorbent nappies
Change nappy and clean skin as soon as possible
Use water or gentle products
Ensure nappy area is dry before replacing nappy
Maximise time not wearing nappy
Complications of nappy rash
Candida infection: clotrimazole cream or miconazole
Cellulitis
Jacquet’s erosive diaper dermatitis
Perianal pseudoverrucous papules and nodules
