CHILD'S HEALTH 2 - Derm, Infect. Disease, Neuro, Psych, Endo, Onc Flashcards
(334 cards)
Outline the pathophysiology of Eczema.
- Filaggrin breaks down to form amino acid pool (used for skin barrier)
- Loss of function mutations in filaggrin gene predispose to breaks in epidermal barrier
So increased exposure and sensitisation to cutaneous antigens, increased eczema risk
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.
Outline the clinical features of eczema
itching (pruritus) is the main symptom, -> results in scratching and exacerbation of the rash
The excoriated areas become erythematous, weeping, and crusted.
Outline some of the treatment options for eczema
The key to maintenance is to create an artificial barrier over the skin to compensate for the defective skin barrier.
This is done using emollients that are as thick and greasy as tolerated, used as often as possible, particularly after washing and before bed.
Flares can be treated with thicker emollients, topical steroids, “wet wraps” (covering affected areas in a thick emollient and applying a wrap to keep moisture locked in overnight) and treating any complications such as bacterial or viral infections.
Give examples of the some of the topical treatments used in eczema
Thin creams:
E45
Diprobase cream
Thick, greasy emollients:
50:50 ointment (50% liquid paraffin)
Hydromol ointment
Diprobase ointment
Steroids - Thicker the skin, stronger the steroid - avoid steroids around eyes face and genitals in children
Mild: Hydrocortisone 0.5%, 1% and 2.5%
Moderate: Eumovate (clobetasone butyrate 0.05%)
Potent: Betnovate (betamethasone 0.1%)
What pathogens can cause skin infections in eczema?
Bacterial - staphylococcus aureus. Treat with flucloxacillin.
Viral - herpes simplex virus (HSV) or varicella zoster virus (VZV). - treat with aciclovir.
What is the presentation of Eczema Herpeticum? (a viral skin infection caused by the herpes simplex virus (HSV) or varicella zoster virus (VZV).
A typical presentation is a patient who suffers with eczema that has developed a widespread, painful, vesicular (sometimes itchy) rash with systemic symptoms such as fever, lethargy, irritability and reduced oral intake.
Pus vesicles can burst leaving punched out ulcers
There will usually be lymphadenopathy (swollen lymph nodes).
What is Stevens-Johnson syndrome? Outline the differentiation between SJS and Toxic Epidermal Necrolysis.
Stevens-Johnson syndrome (SJS) is a Type IV hypersensitivity reaction leads to disproportional immune response causes epidermal necrosis, resulting in blistering and shedding of the top layer of skin
SJS and TEN are a spectrum of the same pathology - Generally, SJS affects less that 10% of body surface area whereas TEN affects more than 10% of body surface area.
name some causes of Stevens-Johnson syndrome
Medications
Anti-epileptics - Carbamazeapine, lamotrigine, Phenytoin
Antibiotics - Penicillins, Ciprofloxacin
Allopurinol
NSAIDs like iburbpfoen
Infections
Herpes simplex
Mycoplasma pneumonia
Cytomegalovirus
HIV
Outline the presentation of SJS.
Starts of non specific - fever, cough, sore throat, sore eyes and itchy skin
develop purple or red rash, that will blister after a few days —-> skin then breaks away and leaves raw tissue underneath
can also happen to the lips and mucous membranes. Eyes can become inflamed and ulcerated. Can affected urinary tract and lungs
Outline the management of SJS
Get to a suitable derm or burns unit!
Good supportive care is essential, including nutritional care, antiseptics, analgesia, and ophthalmology input.
Treatment options include steroids, immunoglobulins and immunosuppressants
What is allergic rhinitis? Name some triggers for it
(Seasonal rhinitis = hayfever)
caused by an IgE-mediated type 1 hypersensitivity reaction. Environmental allergens cause an allergic inflammatory response in the nasal mucosa
Triggers
Tree pollen or grass allergy leads to seasonal symptoms (hay fever)
House dust mites and pets
Mould
What is the management for allergic rhinits?
Avoid the trigger
Oral antihistamines are taken prior to exposure to reduce allergic symptoms:
Non-sedating antihistamines include cetirizine, loratadine and fexofenadine
Sedating antihistamines include chlorphenamine (Piriton) and promethazine
Nasal corticosteroid sprays such as fluticasone and mometasone
What is urticaria? What is it often seen with and why does it happen?
hives. They are small itchy lumps that appear on the skin.
They may be associated with angioedema (swelling of the deeper layers of the skin, caused by a build-up of fluid.) and flushing of the skin
Urticaria are caused the release of histamine and other pro-inflammatory chemicals by mast cells in the skin.
Name some causes of acute urticaria.
Acute urticaria is typically triggered by something that stimulates the mast cells to release histamine. This may be:
Allergies to food, medications or animals
Contact with chemicals, latex or stinging nettles
Medications
Viral infections
Insect bites
Dermatographism (rubbing of the skin)
Name some causes of chronic urticaria.
Chronic inducible urticaria describes episodes of chronic urticaria that can be induced by certain triggers, such as:
Sunlight
Temperature change
Exercise
Strong emotions
Hot or cold weather
Can also be caused by autoimmune conditions eg Lupus
What is the management of urticaria?
Antihistamines are the main treatment for urticaria. Fexofenadine is usually the antihistamine of choice for chronic urticaria. Oral steroids may be considered as a short course for severe flares.
In very problematic cases referral to a specialist may be required to consider treatment with:
Anti-leukotrienes such as montelukast
Omalizumab, which targets IgE
What is the blood test to confirm anaphylaxis?
SERUM MAST CELL TRYPTASE:
Most specific reading for most cell degranulation
Define anaphylaxis
Anaphylaxis a severe, life-threatening, generalised or systemic hypersensitivity reaction. It is characterised by rapidly developing life-threatening airway and/or breathing and/or circulation problems usually associated with skin and mucosal changes
What are some signs/symptoms of anaphylaxis?
o Occurs within minutes and lasts 1-2 hours
o Vasodilation
o Increased vascular permeability
o Bronchoconstriction
o Urticaria (hives)
Tachycardia, Hypotension
Outline what happens in anaphylaxis when a patients primed Mast cells are exposed to the allergen
o The cross-linking of IgE on the cell surfaces causes rapid (mast cell) cellular degranulation and liberation of a number of chemical mediators.
The mediators released by mast cell degranulation include the preformed molecules histamine, protease enzymes, proteoglycans and chemotactic factors.
o Reaction of antigen with IgE on mast cells also stimulates synthesis and release of platelet activating factor (PAF), leukotrienes and prostaglandins.
What are some of the physiological responses to anaphylaxis?
▪ Smooth muscle spasm in the respiratory and GI tracts
▪ Vasodilation
▪ Increased vascular permeability
▪ Stimulation of sensory nerve endings
▪ Increased mucous secretion and bronchial smooth muscle tone, as well as airway oedema
▪ Cardiovascular effects result from decreased vascular tone and capillary leakage. Hypotension, cardiac arrhythmias Tacycardia, syncope and shock can result from intravascular volume loss
What is the Treatment for anaphylactic shock?
ABCDE assessment
IM Adrenaline (1:1000) - (If ineffective then give second IM 1:1000mg Adrenaline Dose as adrenaline has very short half life)
Then
Chlorphenamine - Anti-histamine (H1)
Hydrocortisone - Steroid
What is Kawasaki disease? Who does it most commonly affect?
A systemic vasculitis that affects children.]
It affects young children, typically under 5 years. There is no clear cause or trigger. It is more common in Asian children, particularly Japanese and Korean children. It is also more common in boys
What are some Clinical features of Kawasaki disease?
>5 days fever. - Paracetamol doesn't help And 4/5 of the following: - Conjunctivitis. - Cracked lips/strawberry tongue. - Cervical lymphadenopathy. - Rash - widespread erythematous maculopapular rash - Swollen and red extremities.
TOM TIP: If you come across a child with a fever persisting for more than 5 days, think of Kawasaki disease! A rash, strawberry tongue, lymphadenopathy and conjunctivitis will seal the diagnosis in your exams.