Skin, Infectious Diseases, Neuro, Psych Flashcards
What is eczema
-Chronic atopic condition causes by defects in the normal skin barrier
-leading to inflammation in the skin due to allergens and bacteria entering the gaps in the skin barrier
What does atopic mean
Where there is evidence of IgE antibodies
Presentation of eczema (5)
-dry, red, itchy skin
-flexor surfaces, face and neck particularly sore
-episodic with flare ups
-thickening of the skin (lichenification)
-excoriation - removal of the skin
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 and the associated symptoms.
How does eczema of darker skin present
-may also effect the extensor surfaces
-patches of hyper and hypo pigmentation
DDX of eczema (5)
Psoriasis
Seborrhoeic dermatitis
Fungal infections
Contact dermatitis
Scabies
Management of eczema for maintenance
Create artificial barriers
-emollients - E45 used as much as possible and after washing - lotions, creams, gels, sprays
-soap substitutes
-bandages
Avoid triggers
- hot bathes
- cold weather
- dietary products - food diaries can help
- washing powders
- stress
Topical steroids
Steroid ladder for eczema
Mild - hydrocortisone 0.5%, 1% and 2.5%
Moderate - clobetasone butyrate 0.05% (eumovate)
Potent - betamethasone valerate 0.1% (betnovate)
Very potent - clobetasol propionate 0.05% (dermovate)
What may be used if topical corticosteroids fail in eczema
Topical calcineurin inhibitors
-tacrolimus
-pimecrolimus
When would you use each topical calcineurin inhibitors
Tacrolimus - aged 2+ with moderate to severe disease to avoid skin atrophy and other adverse side effects from steroids
Pimecrolimus - aged 2-16 with moderate disease on face and neck to avoid skin atrophy and other adverse affects from steroids
Common topical steroid side effects
-redness
-stinging and burning
-skin atrophy (thinning)
-acne
-hyperpigmentation
What are the common organisms that cause nfection from eczema skin breakdown (3)
- s.aureus
- herpes simplex virus (HSV-1)
- varicella zoster virus
Tx of s.aureus skin infection from eczema
-Oral Flucloxacillin
-If severe may require IV abx
Presentation of eczema herpeticum
-widespread, vesicular rash (Fluid filled)
-punched out erosions left after vesicles burst
-fever
-lethargy
-irritability
-reduced oral intake
-lymphadenopathy
Investigations of eczema herpeticum
Viral swabs of the vesicles
Treatment of eczema herpeticum
Aciclovir
Complications of eczema herpeticum
-In immunocompromised can be life threatening
-Bacterial superinfection
What is stephens johnson syndrome
-disproportional immune response causing epidermal necrosis
-resulting in blistering and shedding of the top layer of the skin - less than 10% of body surface area affected
Cause of Stephen Johnson syndrome
Medications
-anti epileptics
-allopurinol
-antibiotics
-NSAIDs
Infections
- herpes simplex
- mycoplasma pneumonia
- cytomegalovirus
- HIV
Clinical presentation of Stephen Johnson syndrome
Start with:
Fever
Sore throat
Sore eyes
Itchy skin
Then develop
Purple/red rash
Blistering leaving raw tissue
Shedding of lips
Ulceration of eyes
Mx of Stephen Johnson syndrome
-medical emergency supportive care -
Antiseptic
Analgesia
Nutritional care
Iv fluids - prevent dehydration from skin loss
Ointments for corneal blistering
Tx
Steroids - reduce inflammation
Immunoglobulins
Immunosuppressants - TNF inhibitors e.g infliximab to reduce inflammation
Complications of stephens johnson syndrome
Secondary infection: The breaks in the skin can lead to secondary bacterial infection, cellulitis and sepsis
Permanent skin damage: damage to skin, hair, nails, lungs and genitals.
Visual complications: eye involvement can range from sore eyes to severe scarring and blindness.
What is urticaria
Small itchy lumps that appear on the skin
Pathophysiology of urticaria
-Release of histamine and pro inflammatory chemicals by mast cells
causing dermal oedema due to vessel dilatation
-may be part of an allergic reaction in acute urticaria
-may be part of autoimmune reaction in chronic urticaria
Causes of acute urticaria (6)
Allergies to food, medications or animals
Contact with chemicals, latex or stinging nettles
Medications
Viral infections
Insect bites
Dermatographism (rubbing of the skin)
What is Chronic idiopathic urticaria
Recurrent episodes of chronic urticaria without a clear underlying cause or trigger.
What is chronic inducible urticaria and give some examples
episodes of chronic urticaria that can be induced by certain triggers, such as:
Sunlight
Temperature change
Exercise
Strong emotions
Hot or cold weather
Pressure (dermatographism)
What is autoimmune urticaria
Chronic urticaria associated with an underlying autoimmune condition, such as systemic lupus erythematosus.
Management of urticaria
Antihistamines
-Fexofenadines (chronic)
-Oral steroids for severe flares
Problematic cases
-LRTA
-Cyclosporins
What is allergic rhinitis
-IgE mediated type 1 hypersensitivity reaction to environmental allergens Causing a response in nasal mucosa
Three types of allergic rhinitis
Seasonal e.g hay fever
Perennial (year round) e.g house dust mite
Occupational - associate with work or school
Presentation of allergic rhinitis
-Runny, blocked and itchy nose
-Sneezing
-itchy, red and swollen eyes
How do you diagnose allergic rhinitis
-based on a history - FHX of atopic triad
-skin prick testing for pollen, dust mites etc
Triggers for allergic rhinitis
Tree pollen or grass - seasonal symptoms (hay fever)
House dust mites and pets - persistent symptoms, worse in dusty rooms at night
Pets - persistent symptoms when the pet or their hair, skin or saliva is present
Mould
Management of allergic rhinitis
- AVOID the trigger - e.g dust mite allergy change pillows regularly and good ventilation
-oral antihistamines taken prior to exposure
-nasal corticosteroid sprays - fluticasone taken regularly
Examples of non sedating antihistamines (3)
Cetirizine
Loratadine
Fexofenadine
Examples of sedating oral antihistamines
Chlorphenamine
Promethazine
Correct nasal spray technique
- use opposite hand for whichever side nostril it is
-aim slightly outward from nasal septum - DONT sniff as soon as you spray, but after
- shouldn’t taste it at the back of their mouth
What is anaphylaxis
Severe type 1 hypersensitivity reaction causing compromisation of the airways, breathing or circulation
How does a anaphylactic reaction occur - pathology
-IgE stimulates mast cells to rapidly release histamine and pro inflammatory chemicals - mast cell degranulation
-com promising airways and breathing and circulation
Give 6 Presentations of anaphylaxis
-Urticaria
-Itching
-Angio-oedema, with swelling around lips and eyes
-Abdominal pain
-SOB
-wheeze
-lightheadedness
-swelling of the larynx
How to manage anaphylaxis
A- airway is it secure
B – Breathing: Provide oxygen if required. Salbutamol can help with wheezing.
C – Circulation: Provide an IV bolus of fluids
D – Disability: Lie the patient flat to improve cerebral perfusion
E – Exposure: Look for flushing, urticaria and angio-oedema
Then THREE medications
-intramuscular adrenaline - repeated after 5 minutes if no improvement
-antihistamines - such as cetirizine
-steroids - usually IV hydrocortisone
What should happen after an anaphylactic event (3)
-period of assessment and observation - due to BIPHASIC reactions can occur
-measure serum mast cell tryptase within 6 hours of event
-educate and follow up with child and family - about allergy and how to manage, teach BLS and epi pen administration
When are epi pens given in anaphylaxis
- TO ALL CHILDREN AND ADOLESCENTS with anaphylactic reactions
-children with generalised reactions but with certain risk factors
What are some risk factors that mean that those with only generalised allergic reactions get adrenaline auto injectors (5)
- asthma needing inhaled steroids
-poor access to medical treatment e.g location
- adolescents
- nut or insect sting allergies which are higher risk
-significant co morbidities such as CVD
Steps to use an adrenaline auto injector
The first step is to confirm the diagnosis of anaphylaxis.
Prepare the device by removing the safety cap on the non-needle end. There is a blue cap on EpiPen and a yellow cap on Jext.
Grip the device in a fist with the needle end pointing downwards. The needle end is orange on EpiPen and black on Jext. Do not put your thumb over the end, because if the device is upside down you will inject your thumb with adrenalin and could risk losing it.
Administer the injection by firmly jabbing the device into the outer portion of the mid thigh until the device clicks. This can be done through clothing.
Remove the device and gently massage the area for 10 seconds.
Phone an emergency ambulance. A second dose may be given (with a new pen) after 5 minutes if required.
What are petechiae
Less than 3mm, non blanching, red spots caused by burst blood vessels
What are purpura
3-10mm, non blanching, red/purple macules, papules created by leaking of blood vessels
DDX of non blanching rashes
-Meningococcal septicaemia
-henoch schonlein purpura
-Idiopathic thrombocytopenic purpura (ITP)
-acute leukemias
-Haemolytic uraemic syndrome
-viral illness
-NAI
Management of non blanching rash
URGENT referral and investigation
-definitive Mx dependent on cause
Name 6 Non blanching rash Investigations
FBC
U+E
CRP
ESR
Coag screen
Blood culture
LP
BP
urine dipstick
Meningococcal PCR
Why FBC for non blanching rash investigation
-can detect anemia which can suggest leukemia or HUS
-can detect low white cells which can suggest leukemia
-low platelets can suggest ITP/HUS
Why LP for people with non blanching rash
To diagnose meningitis or encephalitis
Why urine dipstick investigation for non blanching rash
Proteinuria and haematuria can suggest HSP with renal involvement
Or Haemolytic uraemic syndrome
What a Kawasaki disease
Systemic, medium vessel vasculitis affecting young children typically under 5 years
What demographic is kawasakis more common in
Asian children, typically boys - Japanese and Korean
Presentation of kawasakis disease (7)
-persistent high fever for more than 5 days
- red maculopapular rash
-skin peeling on palms and soles
-strawberry tongue
-cracked lips
-cervical lymphadenopathy
-bilateral conjunctivitis
What investigations would you do for suspected kawasakis (6)
FBC - anaemia, leukocytes is and thrombocytosis
LFT - hypoalbuminemia
Inflammatory markers - ESR/CRP raised
Inflammatory markers - ESR raised
Urinalysis - shows raised WBC
ECHO - can show coronary artery pathology
How does kawasakis progress throughout its course
Acute phase - child most unwell with fever, rash and lymphadenopathy
Subacute phase - acute Sx settle - desquamation and arthralgia occurs. Coronary aneurysms may form
Convalescent stage - remaining sx settle and blood tests return to normal
How long does each phase of kawasakis last
Acute: 1-2 weeks
Subacute: 2-4 weeks
Convalescent: 2-4 weeks
Management of kawasakis
High dose aspirin to reduce thrombosis
IVIG reduce coronary artery aneurysm risk
Follow up with echo to monitor
Why is aspirin rarely given in children
Risk of Reye’s syndrome
What is reye syndrome
Condition causing swelling in liver and brain
- aspirin can cause this in children due to damaging mitochondria
What is meningitis
Inflammation of the lining of the brain and spinal cord usually due to viral or bacterial infection
What is meningococcus
A gram negative diplococcus of Nisseria meningitidis
What is meningococcal septicaemia
Meningococcus bacterial infection in the bloodstream
Most common causes of bacterial meningitis in children
-Nisseria meningitidis (meningococcus)
-streptococcus pneumoniae (pneumococcus)
Most common cause of meningitis in neonates and how is it spread to the neonate
Group B strep - usually contracted form birth that live in mothers vagina
Sx of meningitis
Classic triad
-fever
-neck stiffness
-altered mental state
-vomiting
-headache
-photophobia
-seizures
When would you order a lumbar puncture as part of the meningitis investigations
-Children under 1 month
-1-3 months with fever and are unwell
-under 1 year with unexplained fever
What two tests are used to look for meninges irritation
Kernigs test - flex one hip and knee at 90 degrees, and then slowly straighten the knee - will produce spinal pain or some resistance
Brudzinski test - lift their neck off the bed and flex chin to their chest - causes involuntary flexion of their hips and knees
Mx of bacteria meningitis in the community
- urgent stat injection of IM or IV BENZYLPENECILLIN prior to hospital transfer
- if Penecillin allergy transfer to hospital is still the priority
Hospital management of meningitis
-Lumbar puncture if there is time, but skip if patient acutely unwell
-blood test for meningococcal PCR
-give ABX
- under 3 months - cefotaxime plus amoxicillin
- above three months - ceftriaxone
What is given for under 3 month babies in meningitis
Cefotaxime plus amoxicillin
Why is amoxicillin given in under 3 month babies with suspected meningitis
To cover listeria contracted during pregnancy
What Abx is given in addition to the usual in meningitis if there is a risk of pneumococcal infection that is Penecillin resistant
Vancomycin
Why might steroids be used in bacterial meningitis
To reduce the severity of hearing loss and neurological damage
-dexamethasone 4 times daily for 4 days over 3 months
What do you give for meningitis post exposure prophylaxis
Single dose of ciprofloxacin give ASAP
Most common causes of viral meningitis
Herpes simplex virus
Varicella zoster virus
How is viral meningitis treated
-Supportive tx
-Aciclovir
Complications of meningitis
-Hearing loss
-Seizures and epilepsy
-Cognitive impairment and learning disability
-Memory loss
-Cerebral palsy, with focal neurological deficits such as limb weakness or spasticity
Where is a LP inserted
L3-4 invertebral space
What virus causes chickenpox
Varicella zoster virus (VSV)
Presentation of chicken pox
-widespread, erthymatous, fluid filled, lesions starting on the face or trunk
-fever
-itch
-fatigue and malaise
How is chickenpox spread
-highly contagious through direct contact with the lesions
-infected droplets from a cough or a sneeze
Complications of chickenpox (6)
-bacterial superinfection
-dehydration
-conjunctival lesions
-pneumonia
-encephalitis
-shingles
-DIC
What does the reactivation of VSV lead to (2)
Shingles
Ramsay hunt syndrome
What is Ramsay hunt syndrome
Occurs when there is a shingles outbreaks that affects the facial nerve near one of the ears causing hearing loss and facial paralysis
Mx of chicken pox
-usually self limiting
-Aciclovir in immunocompromised patietns/ those at greater risk such as adolescents
-Chlorphenamine for itching
-avoid school
How is chickenpox in a pregnant mother around delivery time managed
-varicella zoster immunoglobulins
-Aciclovir
What is a bacterial superinfection
A second bacterial infection superimposed by the earlier one typically by another bacterial agent
Symptoms of chickenpox
Fever
Malaise
Feeding problems
Vomiting/diarrhoea
Headache
Rash
how to diagnose chickenpox
-usually clinical due to presence of fluid filled rash
-viral polymerase chain reaction
What is fetal varicella syndrome and how is it characterised
An intrauterine infection characterised by one or more of :
-skin scarring
-hypoplasia of limbs (incomplete development)
-neurological disorder e.g learning difficulties
-eye disorder e.g cataracts
In the baby
What organism is measles caused by
Measles morbillivirus
What is the classic presentation of measles
-Fever
-coryzal symptoms
-conjunctivitis
Followed by exanthem - widespread rash
Which groups are at increased risk of measles (3)
Children less than 1year old
Pregnant
Immunocompromised patients
How is measles spread (2)
Person to person contact
Airborne droplets of respiratory secretions
Incubation period of measles
6-21 days
What does incubation period mean
time from acquisition of the pathogen to development of symptoms
Pathophysiology of measles
-virus replicates locally
-then spreads to regional lymph nodes
-spreads to other immune cell sites and around the the body
-leading to symptoms
How long are people infective for when they have measles
5 days before rash appearance
4 days after rash appearance