investigations in primary care

Last reviewed 06/2023

Possible blood tests (and some suggested causes for abnormal results) include:

• full blood count
  • low hematocrit, low hemoglobin level
    • anaemia, cancer, malnutrition
  • altered red cell indexes
    • nutritional deficiencies (e.g., vitamin B12)
  • elevated white blood cell count
    • infection
  • rasied eosinophil count - allergy
    
    
• ESR - infection, neoplasm, inflammatory disease e.g. Sjogren's, SLE
• CRP - infection, neoplasm, inflammatory disease
  
  
• renal biochemstry
  • renal disease, Cushing's, adrenocortical deficiency
    
    
• early morning cortisol - Cushing's, adrenocortical deficiency
  
  
• HbA1c, fasting glucose -diabetes mellitus
  
  
• liver function tests
  • elevated liver enzyme level
    • viral hepatitis, liver disease
  • elevated bilirubin level, elevated alkaline phosphatase level
    • liver disease
      
      
• clotting screen
  • elevated prothrombin time
    • malnutrition, liver disease
      
      
• thyroid function tests
  
  
• raised IgE - allergy

Imaging if suggested from history and examination and available to order from primary care:

Computed tomographic (CT) scanning

• most useful and cost-effective technique for assessing sinonasal tract inflammatory disorders
• coronal CT scans are particularly valuable in assessing paranasal anatomy

MRI

• use of intravenous contrast media helps to better identify vascular lesions, tumors, abscess cavities and meningeal or parameningeal processes
• MRI is superior to CT scanning in the evaluation of soft tissues, but it poorly defines bony structures
• MRI is the technique of choice for assessing the olfactory bulbs, olfactory tracts, facial nerve and intracranial causes of chemosensory dysfunction
  • also the preferred technique for evaluating the skull base for invasion by sinonasal tumors
• Gadolinium enhancement is useful for detecting dural or leptomeningeal involvement at the skull base

Reference:

• Bromley SM. Smell and Taste Disorders: A Primary Care Approach.Am Fam Physician. 2000 Jan 15;61(2):427-436.
• Prescriber 1999; 10 (12): 94.
• Pulse 2004; 63 (47): 80.