Dermatology Flashcards
What is eczema ?
A chronic atopic condition caused by defects in the normal continuity of the skin barrier leading to inflammation in the skin.
How does eczema present ?
Dry, red, itchy and sore patches of skin over the flexor surfaces.
What is the pathophysiology of eczema ?
Eczema is caused by defects in the barrier that the skin provides. Tiny gaps in the skin barrier provide an entrance for irritants, microbes and allergens that create an immune response resulting in inflammation.
What is the management of eczema ?
Maintenance - emollients and specially designed soap substitutes.
Flares - thicker emollients, topical steroids and wet wraps
What are some thin cream emollients ?
E45
Diprobase cream
Oilatum cream
Aveeno
What are some thick cream emollients ?
50:50 ointment
Hydromol
Diprobase
What is the steroid ladder for eczema ?
Mild - hydrocortisone
Moderate - eumovate
Potent - betnovate
Very potent - dermovate
What is eczema herpeticum ?
A viral skin infection caused by the herpes simplex virus or varicella zoster virus.
HSV-1 is the most common causative organism.
How does eczema herpeticum present ?
Widespread, painful, vesicular rash with systemic symptoms such as fever, lethargy, irritability and reduced oral intake.
Lymphadenopathy
What is the management of eczema herpeticum ?
Aciclovir
What are some investigations for eczema herpeticum ?
Viral swabs
What are some complications of eczema herpeticum ?
Immunocompromised
Bacterial superinfection
What is psoriasis ?
A chronic autoimmune condition that causes recurrent symptoms of psoriatic skin lesions.
Genetic component
What is plaque psoriasis ?
Thickened erythematous plaques with silver scales, commonly seen on extensor surfaces and scalp.
What is guttate psoriasis ?
Small raised papules across the trunk and limbs.
Mildly erythematous and slightly scaly.
What is pustular psoriasis ?
Pustules form under areas of erythematous skin. The pus in these areas is not infectious.
Should be treated as a medically emergency
How does psoriasis present ?
Dry flaky scaly
Slightly erythematous skin lesions
Extensor surfaces and scalp
What is the management of psoriasis ?
Topical steroids
Topical vitamin D analogue ( calcipotriol )
Topical dithranol
Phototherapy
What is nail psoriasis ?
Nail changes that can occur in patients with psoriasis.
Nail pitting, thickening, discolouration, ridging and onycholysis.
What are some associations of psoriasis ?
Nail psoriasis
Psoriatic arthritis
Psychosocial implications
What is acne vulgaris ?
An extremely common skin condition often affecting people during puberty and adolescence.
What is the pathophysiology of acne vulgaris ?
Chronic inflammation with or without localised infection, in pockets within the skin known as pilosebaceous unit.
Acne can result from increased production of sebum, trapping of keratin and blockage of the pilosebaceous unit.
How does acne vulgaris present ?
Red, inflamed and sore spots on the skin.
Macules, papules, pustules, comedomes
Blackheads
What is a macule ?
Flat marks on the skin
What is a papule ?
Small lumps on the skin
What is a pustule ?
Small lumps containing yellow pus
What is a comedone ?
Skin coloured papules representing blocked pilosebaceous units
What is a blackhead ?
Open comedones with black pigmentation in the centre
What is the management of acne vulgaris ?
Topical benzoyl peroxide
Topical retinoids
Topical antibiotics
Oral antibiotics
What is isotretinoin ?
A retinoid that works by reducing production of sebum, reducing inflammation and reducing bacterial growth.
Strongly teratogenic
What are some side effects of isotretinoin ?
Dry skin and lips
Photosensitivity of skin to sunlight
Depression, anxiety, aggression and suicidal ideation
Rarely stevens-Johnson syndrome or toxic epidermal necrolysis
What is viral exanthemas ?
An eruptive widespread rash caused by a viral origin.
What are the 6 diseases that cause exanthem ?
First disease - measles
Second disease - scarlet fever
Third disease - rubella
Fourth disease - duke’s disease
Fifth disease - parvovirus B19
Sixth disease - roseola infantum
How does measles spread ?
Highly contagious via respiratory droplets
How does measles present ?
Fever
Coryzal symptoms
Conjunctivitis
Koplik spots
Rash on the face - erythematous and macular
What are some complications of measles ?
Pneumonia
Diarrhoea
Dehydration
Encephalitis
Meningitis
Hearing loss
Vision loss
Death
What is scarlet fever ?
Associated with group A streptococcus infection - tonsillitis
How does scarlet fever present ?
Red-pink, blotchy macular rash with rough sandpiper skin
Fever
Lethargy
Flushed face
Sort throat
Strawberry tongue
What is the treatment of scarlet fever ?
Abx - penicillin V for 10 days
What are some conditions associated with scarlet fever ?
Post -streptococcal Glomerulonephritis
Acute rheumatic fever
How does rubella spread ?
Highly contagious and spread by respiratory droplets
How does rubella present ?
Erythematous macular rash - starts on face and spreads
Mild fever
Joint pain
Sore throat
Enlarged lymph nodes
What is the management of rubella ?
Supportive
The condition is self limiting
What are some complications of rubella ?
Thrombocytopenia
Encephalitis
Congenital rubella syndrome - in pregnancy
What is the triad of symptoms of congenital rubella syndrome ?
Deafness
Blindness
Congenital heart disease
How does parvovirus B19 present ?
Mild fever
Coryza
Muscle aches
Lethargy
‘Slapped cheeks’
What is the management of parvovirus B19 ?
Self limiting
Supportive - fluids and simple analgesia
What are some complications of parvovirus B19 ?
Aplastic anaemia
Encephalitis or meningitis
Pregnancy complications - foetal death
Rarely hepatitis, myocarditis and nephritis
What is erythema multiforme ?
An erythematous rash caused by a hypersensitivity reaction.
How does erythema multiforme present ?
Produces widespread, itchy, erythematous rash
Target lesions - red rings within larger red rings
Stomatitis
What are some other symptoms present in erythema multiforme other than the rash ?
Mild fever
Stomatitis
Muscle ache
Joint ache
Headache
General flu-like symptoms
How is erythema multiforme managed ?
Supportive
Penicillin V
What are some investigations of erythema multiforme ?
CXR to look for mycoplasma pneumonia
What is urticaria ?
Also known as hives
Small itchy lumps that appear on the skin due to histamine release
What is the pathophysiology of urticaria ?
Caused by the release of histamine and other pro-inflammatory chemicals by mast cells in thee skin.
May be part of an allergic reaction or autoimmune reaction
What are some causes of acute urticaria ?
Allergies to food, medications or animals
Contact with chemicals, latex or stinging nettles
Medications
Viral infections
Insect bites
Dermatographism
What is chronic urticaria ?
An autoimmune condition where autoantibodies target mast cells and trigger them to release histamines and other chemicals.
What is the management of urticaria ?
Antihistamines usually fexofenadine
Oral steroids can be given
What is chicken pox ?
Caused by varicella zoster virus
Highly contagious
How does chicken pox present ?
Widespread, erythematous, raised vesicular blistering lesions
Fever
Itchy
Fatigue
How does chicken pox spread ?
Highly contagious and spread through direct contact with the lesions or through infected droplets from a cough or sneeze.
What are some complications of chicken pox ?
Bacterial superinfection
Dehydration
Conjunctival lesions
Pneumonia
Encephalitis
Shingles or Ramsey Hunt syndrome
What can happen if a woman gets chicken pox 28 weeks into pregnancy ?
Developmental problems in the foetus
- congenital varicella syndrome
What can happen if the mother has chicken pox at the time of delivery ?
Life threatening neonatal infection
How is chicken pox treated in neonates after birth ?
Varicella zoster immunoglobulins
Aciclovir
What is the management of chicken pox ?
Self limiting
Aciclovir - if immunocompromised
Calamine lotion and antihistamines
What causes hand, foot and mouth disease ?
Coxsackie A virus
How does hand, foot and mouth disease present ?
Starts with an URTI
Tiredness
Sore throat
Dry cough
Fever
Mouth ulcers
What is the management of hand, foot and mouth disease ?
No treatment
Supportive - fluids and analgesia
What are some complications of hand, foot and mouth disease ?
Dehydration
Bacterial superinfection
Encephalitis
What is molluscum contagiosum ?
Viral skin infection caused by a virus which is a type of poxvirus
What are some features of molluscum contagiosum ?
Small, flesh coloured papules
Appear in crops
What is the management of molluscum contagiosum ?
No treatment
Avoid sharing towels or close contact
What are some specialist treatment options for molluscum contagiosum ?
Topical potassium hydroxide, benzoyl peroxide
Surgical removal and cryotherapy
What is pityriasis rosea ?
Generalised self limiting rash of an unknown cause.
Caused by a virus such as herpes virus
How can pityriasis rosea present ?
Headache
Tiredness
Loss of appetite
Herald patch - faint red scaly oval lesion
Generalised itch
Low grade pyrexia
What is the management of pityriasis rosea ?
No treatment
Emollients, topical steroids or sedating antihistamines
What is seborrhoeic dermatitis ?
An inflammatory skin condition that affects the sebaceous glands.
How does seborrhoeic dermatitis present ?
Erythema, dermatitis and crusted dry skin
Crusted, dry flaky scalp - cradle cap
What is infantile seborrhoeic dermatitis ?
A crusted flaky scalp
Self limiting and usually resolves in 4 months
What is the treatment of infantile seborrhoeic dermatitis ?
Applying baby oil, vegetable oil or olive oil
Topical anti-fungal cream - clotrimazole or miconazole
What is the treatment of seborrhoeic dermatitis of the scalp ?
Ketoconazole shampoo
Topical steroids
What is ringworm ?
A fungal infection of the skin.
What is tinea capitis ?
Refers to ringworm affecting the scalp
what is tinea pedis ?
Refers to ringworm affecting the feet also known as athletes foot
What is tinea cruris ?
Refers to ringworm of the groin
What is tinea corporis ?
Refers to ringworm on the body
What is onchyomyosis ?
Refers to a fungal nail infection
What is the management of ringworm ?
Anti-fungal creams - clotrimazole
Anti-fungal shampoo - ketoconazole
Oral anti-fungal medications - fluconazole
What is the management of fungal nail infections ?
Amorolfine nail lacquer for 6-12 months
Resistance - oral terbinafine
What is nappy rash ?
Contact dermatitis in the nappy area.
Caused by friction between the nappy and contact with urine and faeces.
What are some risk factors of nappy rash ?
Delayed changing of nappies
Irritant soap products and vigorous cleaning
Certain types of nappies
Diarrhoea
Oral antibiotics predispose to candida infection
Pre-term infants
How does nappy rash present ?
Sore, red, inflamed skin in the nappy area
What are some signs that point to a candida infection rather than nappy rash ?
Rash extending into the skin folds
Larger red macules
Well demarcated scaly border
Circular pattern to the rash
What is the management of nappy rash ?
Switching to highly absorbent nappies
Change the nappy as soon as wetting or soiling
Ensure nappy is dry
What are some complications of nappy rash ?
Candida infection
Cellulitis
What is scabies ?
Tiny mites that burrow under the skin causing infection and intense itching.
They lay eggs in the skin leading to further infection.
How does scabies present ?
Incredibly itchy small red spots
Track marks - where the mites have burrowed
Rash between the finger webs
What is the treatment of scabies ?
Permethrin cream - apply to whole body
Whole household should be treated
All clothes, bedclothes, towels and other materials should be washed on a hot wash.
What is head lice ?
Parasites which causes infestations of the scalp.
Commonly known as nits however nits are egg shells that ave hatched or contain unviable embryos.
How does head lice spread ?
Spread by close contact with someone that has head lice usually in schools or amongst family members.
Head to head or sharing towels or combs
How does head lice present ?
Itchy scalp
Often the nits ( eggs ) and even the lice themselves are visible when examining the scalp.
What is the management of head lice ?
Dimeticone 4% lotion can be applied to the hair and left to dry.
Repeated 7 days later
Special fine combs can be used to comb out the nits and lice
What is a non-balancing rash ?
Caused by bleeding under the skin
What is petechiae ?
Small non-blanching, red spots on the skin caused by burst capillaries
What is purpura ?
Larger non-blanching red purple macules or papules created by leaking of blood from vessels under the skin
If a child is presenting with a non blanching rash what differential is most concerning ?
Meningococcal septicaemia
What are some differentials for a non-blanching rash ?
Meningococcal septicaemia
Henoch-Schonlein purpura
Idiopathic thrombocytopenic purpura
Acute leukaemia
Haemolytic uraemic syndrome
What are some investigations that should be performed when a shield has a non-blanching rash ?
FBC
U&E’s
CRP
ESR
Coag screen
Blood culture
LP
Urine dip
How should a patient with a non-blanching rash be treated ?
Treated for meningococcal septicaemia
Definitive management dependent on the underlying cause
What is erythema nodosum ?
A condition where red lumps appear across the patients shins.
It is caused by inflammation of the subcutaneous fat on the shins. There is a hypersensitivity reaction.
What are some associations with the hypersensitivity reaction of erythema nodosum ?
Streptococcal throat infections
Gastroenteritis
Mycoplasma pneumoniae
TB
Pregnancy
Medications - COCP and NSAIDs
What are some chronic diseases associated of erythema nodosum ?
Sarcoidosis
IBD
Lymphoma
Leukaemia
How does erythema nodosum present ?
Reed, inflamed, subcutaneous nodules across both shins. The nodules are raised and can be painful and tender.
What are some investigations to perform when suspecting erythema nodosum ?
CRP and ESR
Throat swab
CXR
Stool microscopy and culture
Faecal calprotectin
What is the management of erythema nodosum ?
Conservatively with rest and analgesia
Steroids may help settle it
What is impetigo ?
A superficial bacterial skin infection usually caused by staph aureus.
Golden crust - characteristic of the infection
What is non-bullous impetigo ?
Typically occurs around the nose or mouth.
The exudate from the lesions dries and forms a golden crust.
What is the management of non-bullous impetigo ?
Topical fusidic acid for localised impetigo.
Oral flucloxacillin is used to treat more wide spread or severe impetigo
Stay off school
What is bullous impetigo ?
Always caused by staph aureus
Produces epidermolytic toxins that break down the proteins that hold the skin cells together. This causes vesicles to form which then burst and cause the golden crust.
When is bullous impetigo more common ?
Neonates
Children under 2
What is the treatment of bullous impetigo ?
Abx - flucloxacillin oral or IV
What are some complications of impetigo ?
Cellulitis
Sepsis
Scarring
Post-strep glomerulonephritis
Staph scalded skin syndrome
Scarlet fever
What is staph scalded skin syndrome ?
A condition caused by a type of staph aureus bacteria that produces epidermolytic toxins. These toxin are protease enzymes that break down the proteins that hold the skin cells to ther.
How does staph scaled skin syndrome present ?
Generalised patches of erythema.
Thin and wrinkled skin
Bullae
Nikolsky sign - gentle rubbing of the skin causes it to peel
Fever
Lethargy
What is the management of staph scalded skin syndrome ?
Treatment with IV fluids
What is stevens-Johnson syndrome ?
Disproportional immune response causing epidermal necrosis resulting in blistering and shedding of the top layer of the skin. Affects less than 10% of the body
Why is toxic epidermal necrolysis different to Steven-Johnson syndrome ?
It affects more than 10% of the body
What are some medications that can cause Steven-Johnson syndrome ?
Anti-epileptics
Antibiotics
Allopurinol
NSAIDs
What are some infections that can cause Steven-Johnson syndrome ?
Herpes simplex
Mycoplasma pneumoniae
Cytomegalovirus
HIV
How does Steven-Johnson syndrome present ?
Start with non-specific symptoms - fever, cough, sore throat, itchy skin
A few days later - blistering starts, skin starts too break away and shed leaving raw tissue underneath.
Eyes can become ulcerated and inflamed.
What is the management of Steven-Johnson syndrome ?
Analgesia
Steroids
Immunoglobulins
Immunosuppressants
What are some complications of Steven Johnson syndrome ?
Secondary infection - cellulitis and sepsis
Permanent skin damage
Visual complications
