Current Allergy and Clinical Immunology - March 2008

the presence of chronic infections may alert toX-linked agammaglobulinaemia with inability to formimmunoglobulins due to absence of B cells.• Respiratory and ENT exams frequently reveal evidenceof scarred or perforated tympanic membraneswith purulent discharge and bronchiectasis mayalready be established• GIT examination may show hepatosplenomegalydue to chronic immune activation or hepatomegalywith or without jaundice as part of T-cell disordersand intrahepatic chronic infections.• Neurological exam should be evaluated particularlyin the presence of telangiectasia – although ataxiaand immunodeficiency can also occur without thehallmark ocular findings (Fig. 3).Fig. 1. Dysplasia and immunodeficiency – dysplasticteeth.history does not exclude PID which can also bedue to new mutations.• In South African practice adequacy and accuracyof the history must be evaluated critically in thecontext of multiple caretakers of the extendedfamily and language differences.EXAMINATIONA thorough physical examination of these childrenrequires additional time and a normal exam does notexclude significant immune defects. Exposure to thepathogen to which the patient is unduly susceptiblemay not have occurred yet, a protected environmentmay have limited exposure to pathogens and breastfeedingmay have aided in defence against infectionearly in life. The anxious and worried parents shouldnever be ignored, as they see their child for much moretime than the usual consultation and they are mostlyjustified in their concerns.• General appearance gives many clues to the alertmedical practitioner or nurse, especially with featuresof chronic illness such as pallor, wasting, clubbingand especially listlessness for which there is noother obvious explanation.• Detailed weight and height mapping and longitudinalanalysis give important information for onset ofillness and response to intervention.• Skin and mucosal features as mentioned abovemay be visible, and scarring from chronic infectionsor disseminated Varicella may alert to PID.• Dysmorphic features of DiGeorge anomaly withmicrognathia or those of trisomy 21 may be apparent.• Absence of lymphoid including tonsillar tissue inFig. 2. X-linked agammaglobulinaemia – family tree (SPienaar).Fig. 3. Ocular telangiectasia.LABORATORY EXAMINATIONSelective laboratory investigations are available atreferral centres of major hospitals in South Africa forassessment of a child who has been identified for furtherinvestigation after the above history and examinationapproach.The investigations where possible should be discussedwith the relevant immunology or general laboratories inconsultation with a pathologist/immunologist/infectiousdisease specialist to arrive at a correct diagnosisfor appropriate treatment.A modified approach of the guidelines as proposed bythe Jeffrey Modell Foundation 6 (© 2003 JeffreyModell Foundation) for PID investigation suitable forSouth Africa will result in sensible laboratory investigation.The adapted model of screening in bold also allowsfor the high prevalence of HIV/AIDS, tuberculosis andmalnutrition in South Africa.Stage 1Initial laboratory screen• Full blood count and differential count• IgG,M,A including IgE• HIV screenWhere indicated a sweat test for cystic fibrosis (Fig. 4),a Mantoux test and chest X-ray to exclude tuberculosisare performed. The Mantoux test and whereavailable trychophyton and Candida skin tests can beused to document presence of delayed-type hypersensitivity.Stage 2Where B-cell-related deficiencies are suspected a specificantibody response to universal vaccination withtetanus, diptheria and pertussis protein antigens is performed.10 Current Allergy & Clinical Immunology, March 2008 Vol 21, No. 1