Overview X-linked agammaglobulinaemia (XLA) is a rare primary immunodeficiency caused by mutations in the Bruton’s tyrosine kinase (BTK) gene, leading to failure of B-cell maturation. It results in profound hypogammaglobulinaemia and susceptibility to recurrent bacterial infections, particularly with encapsulated organisms. It usually presents after 6 months of age (once maternal IgG wanes). Prevalence is ~1 […]

Overview Wiskott–Aldrich syndrome is a rare X-linked recessive primary immunodeficiency caused by mutations in the WAS gene, leading to defective actin cytoskeleton regulation in hematopoietic cells. It presents with the triad of eczema, recurrent infections, and thrombocytopenia with small platelets. Patients are prone to autoimmunity and malignancy. Incidence is ~1 in 100,000 live male births. […]

Overview Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency, characterised by profound defects in both humoral (B-cell) and cellular (T-cell) immunity. It presents in infancy with recurrent, severe, and opportunistic infections, chronic diarrhoea, and failure to thrive. Without curative therapy, most infants die within the first year of life. Incidence is […]

Overview Selective IgA deficiency is the most common primary immunodeficiency, defined by very low or absent serum IgA levels with normal levels of other immunoglobulins (IgG, IgM). Many patients are asymptomatic, but some develop recurrent mucosal infections, allergic disease, or autoimmune disorders. Prevalence is estimated at 1:300 to 1:700 in Caucasian populations. Diagnosis is often […]

Overview Leukocyte adhesion deficiency (LAD) is a rare primary immunodeficiency characterised by recurrent bacterial and fungal infections, impaired wound healing, and absence of pus formation due to defective leukocyte adhesion and migration. It results from genetic defects in leukocyte integrins or signalling pathways, preventing neutrophil extravasation from blood vessels into tissues. LAD has an estimated […]

Overview Hyper-IgE syndrome (HIES) is a rare primary immunodeficiency characterised by markedly elevated serum IgE, recurrent staphylococcal skin and lung infections, eczema, and connective tissue/ skeletal abnormalities. Most commonly caused by autosomal dominant mutations in STAT3, it results in impaired Th17 cell differentiation and defective neutrophil chemotaxis. Autosomal recessive forms (DOCK8, TYK2 mutations) present with […]

Overview DiGeorge syndrome (22q11.2 deletion syndrome) is a congenital immunodeficiency and multisystem disorder caused by a microdeletion on chromosome 22. It leads to defective development of the third and fourth pharyngeal pouches, resulting in thymic hypoplasia/aplasia, hypocalcaemia due to parathyroid hypoplasia, and congenital heart defects. Prevalence is estimated at 1 in 4000 live births. Clinical […]

Overview Complement deficiencies are rare primary immunodeficiencies resulting from inherited absence or dysfunction of complement proteins, regulators, or receptors. They predispose to recurrent bacterial infections, autoimmune disease (particularly systemic lupus erythematosus–like syndromes), and in some cases angioedema. Complement proteins play a central role in innate immunity by opsonisation, chemotaxis, and direct lysis of pathogens via […]

Overview Common Variable Immunodeficiency (CVID) is the most frequent clinically significant primary antibody deficiency, characterised by hypogammaglobulinaemia and impaired antibody responses. It typically presents with recurrent bacterial infections, autoimmunity, granulomatous disease, and an increased risk of malignancy. CVID affects both sexes equally, with a prevalence of ~1 in 25,000–50,000 individuals. Diagnosis is often delayed, with […]

Overview Chronic granulomatous disease (CGD) is a rare, inherited primary immunodeficiency characterised by defective function of the NADPH oxidase enzyme complex in phagocytes, leading to failure of the oxidative burst required for intracellular killing of pathogens. This results in recurrent, often life-threatening bacterial and fungal infections, particularly with catalase-positive organisms, and predisposes to granuloma formation […]

AuthorMegan MinerArmando Faigl Overview Pertussis, also known as “whooping cough”, is a contagious, acute respiratory infection caused by the bacterium Bordetella pertussis. In babies, the infection can sometimes lead to pneumonia and occasionally brain damage and can even be life threatening. Older children and adults can get whooping cough and can spread it to others, […]

Overview In this common disorder of adolescence the tibial tubercle becomes painful and ‘swollen’. Although often called osteochondritis and apophysitis, it is nothing more than a traction injury of the apophysis into which part of the patellar tendon is attached. Osgood-Schaltter disease typically occurs during the early adolescent growth spurt between 10-15 years of age, […]

Meningitis 5 year old presents with non-blanching rash, fever, headache, photophobia and neck stiffness. Aetiology Clinical presentation Investigations Treatment Complications Pertussis 8 month old presents with paroxysmal cough and fever. Parents states the baby coughs all night and has episodes of post-tussive emesis (vomiting). The baby is not up to date with their vaccination. Aetiology […]

Classification Large-vessel vasculitis Medium-sized vessel vasculitis Small-vessel vasculitis Other vasculitides

Overview Kawasaki disease is an acute systemic vasculitis affecting small and medium-sized vessels predominantly affecting children under 5 years old. It is the leading cause of acquired heart disease in children in developed countries. Kawasaki is often self-limiting, but 20–25% risk of coronary artery aneurysms if untreated 1. Anatomy & Physiology Affects medium-sized muscular arteries, […]

Classical Exanthem Overview Exanthem refers to the cutaneous manifestation of a viral illness (enanthem is the manifestation in the mouth). Historically, 6 exanthems have been recognised, 4 of which are viral. However, obviously there are much more common exanthems. The six described are: Measles Overview  Also known as rubeola or first disease it is a […]

Overview Henoch Schonlein Purpura is a IgA vasculitis characterised by the Tetrad: palpable purpuric petechial rash, abdominal pain, kidney involvement and arthralgia. Aetiology is unknown but thought to have a genetic predisposition. Clinical Manifestation Diagnosis Differential Diagnosis of Purpura/Petechiae in a child Investigation Treatment Acute management Ongoing management Complications and Prognosis

Overview Otitis media (OM) is one of the most common infections in children. OM is inflammation of the middle ear and is usually secondary to bacterial and/or viral infection. It is a complication of eustachian tube dysfunction that occurred during an acute viral upper respiratory tract infection (URTI). The URTI causes effusion in the middle ear […]

Overview Seizures are a common occurrence in children. 8% will have at least one seizure by 15 years of age. A seizure is the result of an abnormal paroxysmal discharge by cerebral neurons. Many underlying conditions and neurological challenges may provoke seizures, and in over 50% of children seizures are isolated events associated with either a fever […]

Overview Gastroenteritis continues to cause significant morbidity in developed and developing countries. The most common cause are viral and bacterial including: Gastroenteritis is usually self-resolving. Parasitic infection are uncommon but can be dangerous. Clinical Manifestation It is important to assess state of dehydration because this will tailor treatment. Dehydration can be either mild, moderate or […]

Overview Urinary Tract infections (UTIs) in children are common and usually carry low risk. UTIs are often non-specific and can not be diagnosed on symptoms alone. A clean specimen (urine) is required for the diagnosis of UTI. Any child who is unwell, and most children under 6 months, should be admitted for IV antibiotics. The […]

Overview Umbilical hernias are one of the most common surgical conditions in infants and children. In infantile umbilical hernia there is a pathological failure of obliteration of umbilical defect. Umbilical hernia can also occur in adults and is usually acquired due to increased intrabdominal pressure due to obesity, pregnancy, ascites. Management is surgery. Anatomy and Physiology Umbilical Cord […]

Overview Septic arthritis refers to infection in a joint; it is usually caused by bacteria but can be caused by fungi or mycobacteria. Septic arthritis due to bacterial infection is often a destructive form of acute arthritis. Pathophysiology Septic arthritis involves bacterial infection of a synovial joint. Proteolytic enzymes released by host inflammatory cells and […]

Overview Birth defects are the leading cause of perinatal and post- neonatal deaths, and result in substantial morbidity and disability in developed countries. There is a wide variety of mechanisms including genetic, environmental and multifactorial. Major birth defects affect 2–3% of live-borns, and minor birth defects affect 15%. Preventative strategies remain limited, but include maternal folic acid supplementation, […]