What blood tests are recommended for a patient presenting with fatigue, leukotrichia (white hair), and decreased libido, in accordance with Australian Medicare MBS (Medicare Benefits Schedule) rules?

Recommended Blood Tests for Rayanne's Symptoms

For a patient presenting with fatigue, white hair (leukotrichia), and low libido without prior nutrient deficiencies, order morning serum total testosterone as the primary initial test, followed by thyroid function tests (TSH, free T4), and a complete blood count to evaluate for common causes of these symptoms that meet Australian Medicare MBS criteria.

Core Testing Panel

Essential Hormone Testing

• Morning total testosterone should be the first-line test for evaluating fatigue and low libido symptoms, as these are classic manifestations of testosterone deficiency 1
• The test must be performed in the early morning (around 8 AM) when testosterone levels are typically highest 2, 1
• If the initial testosterone is low (<300 ng/dL equivalent), a second morning measurement is required for confirmation 1
• Serum testosterone testing is specifically recommended in males with fatigue and loss of libido 2, and DHEA replacement should be considered in women with low libido and/or energy 2

Thyroid Function Assessment

• TSH and free T4 are essential tests, as unexplained fatigue and hair loss are recognized symptoms of hypothyroidism 2
• These tests are covered under MBS when clinically indicated for fatigue and related symptoms 2
• High TSH with low free T4 indicates primary hypothyroidism 2

Basic Hematology

• Complete blood count (CBC) with differential to evaluate for anemia and other hematologic causes of fatigue 2
• This is a standard MBS-covered test for fatigue evaluation 2

Follow-Up Testing Based on Initial Results

If Testosterone is Low

• Luteinizing hormone (LH) to establish the etiology of testosterone deficiency (primary vs. secondary) 1
• Serum prolactin if testosterone is low with low/normal LH levels 1
• Follicle-stimulating hormone (FSH) may be indicated to further characterize gonadal function 2

If Thyroid Dysfunction is Suspected

• Thyroid peroxidase (TPO) antibody testing is warranted if biochemical hypothyroidism is confirmed 2

Additional Metabolic Screening

• Fasting blood glucose to exclude diabetes, which can cause fatigue 2
• Electrolytes, blood urea nitrogen, and creatinine if clinically indicated 2
• Lipid profile may be considered as part of comprehensive metabolic assessment 2

Important Clinical Considerations

Regarding White Hair (Leukotrichia)

• White hair alone is not typically associated with nutrient deficiencies requiring blood testing 3
• Leukotrichia is most commonly associated with vitiligo or normal aging rather than systemic nutritional deficiencies 3
• Do not order extensive micronutrient panels without specific clinical indicators beyond white hair, as these are often not MBS-covered for this indication

Testing Protocol Requirements

• At least two separate morning testosterone measurements are required before diagnosing testosterone deficiency 1
• Single measurements should not be used for diagnosis due to diurnal variation 1
• Screening questionnaires alone without laboratory confirmation are not recommended 1

Common Pitfalls to Avoid

• Avoid ordering comprehensive nutrient panels (vitamin B12, folate, iron studies, vitamin D) without specific clinical indicators beyond the symptoms described, as MBS may not cover these without documented deficiency risk factors 1
• Do not rely on non-morning testosterone measurements, which may be falsely low 1
• Do not order tests for hypophysitis workup (ACTH, cortisol, MRI pituitary) unless there are specific indicators like severe headaches or visual changes, as these symptoms are related to immune checkpoint inhibitor therapy, not applicable to this patient 2

MBS Compliance Notes

• The tests recommended above (morning testosterone, TSH, free T4, CBC) are covered under MBS when ordered for clinically appropriate indications such as fatigue and low libido 2, 1
• Ensure documentation clearly links the symptoms (fatigue, low libido) to the tests ordered to meet MBS requirements
• Extensive micronutrient screening without specific risk factors or documented deficiencies may not meet MBS criteria and could result in out-of-pocket costs for the patient