Immune Presentations

Question 1

What is immunodeficiency, how does it present and what is its DDx?

Answer 1

Types

• Combined = SCID, CID
• Well-defined = DiGeorge syndrome, Hyper IgE Syndrome
• Ab def = common variable immune deficiency (CVID)
• Immune dysregulation
• Phagocytic = chronic granulomatous disorder (CGD)
• Innate
• Autoinflam
• Complement def

S+S = Severe, Persistent, Unusual, Recurrent infections and with a history of PID Running in the family (SPURR), failure to thrive

DDx = Chronic Granulomatous Disease, HIV infection, congenital rubella

Question 2

What is an adverse drug reaction, how does it present and what is its DDx?

Answer 2

ADR is an injury caused by taking medication - may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs

Report to the Medicines and Healthcare products Regulatory Agency (MHRA), using the Yellow Card Scheme

S+S = erythema, pruritus , oedema, blisters or peels, vision problems, throat tightness, trouble breathing, tingling, dizziness, wheezing

DDx = allergy

Question 3

What is food allergy, its cause, and symptoms?

Answer 3

Food allergy is an abnormal response of the body to a certain food

Sensitisation, re-exposure - IgE, degranulation of mast cells, release of histamine

Non-IgE mediated

S+S = urticaria, itching in the mouth, trouble breathing, stomach pains, vomiting, diarrhoea, low BP, tight throat

• IgE mediated = minutes after
• Non-IgE mediated = hours after

Milk, nuts, eggs, wheat, soy, fish, shellfish

Hx = rash, onset, frequency, first time, illness, location, itching/distress, breathing diff, atopy Hx, diet, immunisations, exposure to nuts/eggs/fish, FH allergy, smoking, pets, growth/devel, daily activities

Question 4

How should food allergy be Ix?

Answer 4

Food diary

Immunoassay (specific IgE)

Skin prick test

For both IgE-mediated and non-IgE-mediated food allergies, the gold-standard Ix in cases of doubt is exclusion of the relevant food under a dietitian’s supervision, followed by a double-blind placebo-controlled food challenge (DBPCFC)

Question 5

How should food allergy be managed?

Answer 5

Food avoidance

Anaphylaxis = EpiPen

Question 6

What is Immune Thrombocytopenic Purpura, its causes and presentation?

Answer 6

Characterised by idiopathic (spontaneous) thrombocytopenia (low platelet count) causing a purpuric rash (non-blanching rash)

TII hypersensitivity reaction = prod of Ab that target and destroy platelets

Cause = spontaneous, triggered by viral infection

S+S =

• Bleeding, for example from the gums, epistaxis or menorrhagia
• Bruising
• Petechial or purpuric rash, caused by bleeding under the skin

Question 7

How should suspected ITP be Ix?

Answer 7

FBC: Hb, WCC

Plt

Question 8

What is the management for ITP?

Answer 8

Prednisolone

IV immunoglobulins

Blood transfusions if required

Platelet transfusions - only work temporarily because the Ab against plt will begin destroying the transfused plt as soon as they are infused

Advice

• Avoid contact sports
• Avoid IM injections and procedures such as LP
• Avoid NSAIDs, aspirin and blood thinning medications
• Advice on managing nosebleeds
• Seek help after any injury that may cause internal bleeding, for example car accidents or head injuries

Question 9

Outline the possible complications of ITP

Answer 9

Chronic ITP

Anaemia

Intracranial and subarachnoid haemorrhage

Gastrointestinal bleeding