Paediatric rheumatology and immunology Flashcards
HSP - what does it stand for, and what is another name for it
Henoch-Schonlein purpura
AKA IgA vasculitis
Classic tetrad of HSP
- Palpable purpura in absence of thrombocytopaenia or coagulopathy
- Arthritis/arthralgia
- Abdominal pain
(4. Renal disease)
Epidemiology of HSP
Most common form of systemic vasculitis in children
Peak incidence between 4-6y
Slight male predominance
Rarely occurs in summer months
5% higher in patients with familial mediterranean fever
Presentation of HSP
50% preceded by URTI
Palpable purpura - mainly on extensor surfaces of the lower limb and the buttocks)
Arthritis/arthralgia (usually lower limb large joints)
Abdominal pain +/- intussuception (colicky pain in 50%)
Renal disease
May be associated with subcutaneous oedema (scrotum, face, hands)
Manifestations may develop over the course of days-weeks and may vary in their order of presentation
Purpura and joint pain are usually the presenting symptoms
Investigations in suspected HSP
Urine dipstick - MCS if haematuria
CBE
EUC
Blood culture
Management of HSP
Symptomatic (NSAIDs and analgesia) Prednisolone 1mg/kg if severe abdo or joint pain Admit if (abdominal or renal complications, or for severe symptoms needing supportive treatment) Discharge with information for family, ensure follow-up
Follow-up required for HSP
Follow-up early on to ensure remission of symptoms (rash usually last to go)
Urine checked regularly first 6 months (renal involvement can present up to 6 months after initial presentation)
BP checked 3-monthly over first 6 months
Rationale for prednisolone in HSP
Symptomatic relief only
Shortens duration of abdominal and joint pain
Does not improve rate of long-term renal complications
May reduce risk of abdominal complications
Diagnostic criteria for Kawasaki disease
Fever for 5 or more days
PLUS 4 out of 5:
- polymorphous rash
- bilateral (non purupent) conjunctival injection
- Mucous membrane changes (reddened/dry cracked lips, strawberry tongue, diffuse redness of oral or pharyngeal mucosa)
- Peripheral changes (erythema of palms or soles, oedema of hands/feet, in convaescence desquamation)
- Cervical lymphadenopathy (usually unilateral, single and painful
+ exclusion of diseases with similar presentation (TSS, scalded skin syndrome, scarlet fever, measles, Steven Johnson’s, drug reaction)
Definition of atopy
the ability of an individual to form specific IgE antibodies to one or more common inhaled aeroallergens
Definition of an allergen
An antigen (usually a protein) that is recognised by the immune system, is usually harmless, and induces an allergic inflammatory response
Atopic diseases (types)
Eczema
Asthma
Allergic rhinoconjunctivitis
Epidemiology of Kawasaki disease (age, gender, ancestry)
Males more than females
90% below the age of 5
Highest incidence in children of Asian (esp Japanese) descent
Pathophysiology in Kawasaki disease
Systemic inflammatory illness particularly affecting medium-sized arteries (e.g. coronary), inflammatory cell infiltration into vascular tissue causes blood vessel damage
Strawberry tongue occurs due to sloughing of filiform papillae and denuding of inflamed glossal tissue
Investigations in Kawasaki disease
CRP/ESR/Ferritin all increased
Normocytic normochromic anaemia is common
Pyuria
EUC - hypoNa+ associated with higher risk of CA aneurysms
Echo at time of diagnosis and repeat 6-8 weeks later if normal
