Recurrent fever in children (PFAPA or Marshall syndrome, cyclic neutropenia, other autoinflammatory diseases)

Laboratory tests during the fever (ideally within the first 24 to 48 hours)

• FBC
• CRP
• Serum electrolytes
• Urea
• Serum creatinine
• Blood cultures
• ASTif neededThe PNDS (French national protocol for diagnosis and care) asks for them during the attack only in case of abdominal pain ^[1].
• ALTif neededThe PNDS (French national protocol for diagnosis and care) asks for them during the attack only in case of abdominal pain ^[1].
• Urinary mevalonic acid during the attack (if onset before 1 year or digestive signs; to be discussed with the paediatrician)if neededScreens for mevalonate kinase deficiency, to be considered first if digestive signs are present or if onset is very early; good negative predictive value; the urine sample is sent by the community laboratory to the reference laboratory ^[1].

Urine tests

• Urine dipstick
• Urine microscopy and culture (if dipstick positive)if neededThe PNDS asks for a “urinary assessment” during the attack ^[1]; recurrent urinary tract infections are among the infectious causes to rule out ^[1].

Laboratory tests between attacks

• FBC
• CRP
• Serum immunoglobulins (IgG, IgA, IgM)
• Urea
• Serum creatinine

Laboratory tests

• FBC with blood film (looking for Howell-Jolly bodies)
• Serum immunoglobulins (IgG, IgA, IgM)
• Vaccine serologies (tetanus, diphtheria, Haemophilus, pneumococcus) after primary vaccination
• Natural blood group antibodies (isohaemagglutinins, if over 2 years)if neededThe PNDS adds them to the immunodeficiency work-up in children over 2 years ^[1].
• HIV serology (in a child of 18 months or more)if needednon-French guidelineThe American AAFP review (2013) includes an HIV test in the initial work-up of suspected immunodeficiency in a child, as HIV infection resembles T-cell immunodeficiency clinically ^[5]. Before 18 months, maternal antibodies transferred across the placenta require a viral test ^[5]. The French PNDS places it in the further tests done in a specialist setting ^[1]. American level C recommendation (expert opinion) ^[5].
• Total complement CH50 (to rule out complement deficiency)if needednon-French guidelineThe American AAFP review (2013) includes complement in the initial work-up of suspected immunodeficiency in a child: a normal CH50 rules out a clinically significant complement deficiency; if abnormal, the alternative pathway is investigated ^[5]. The French PNDS places it in the further tests done in a specialist setting ^[1]. American level C recommendation (expert opinion) ^[5].
• Serum albumin (if immunoglobulins low)if needednon-French guidelineLow immunoglobulins: the American AAFP review (2013) asks for albumin, hypoalbuminaemia pointing to renal loss or digestive malabsorption as the cause of the deficiency ^[5]. See also the page “Hypogammaglobulinaemia”.

Twice a week for 4 to 6 weeks

• FBC (twice a week, 8 to 12 samples)