From the Guidelines
Laboratory tests for alopecia should include a complete blood count (CBC), comprehensive metabolic panel, thyroid function tests (TSH, free T4), serum ferritin, vitamin D level, and antinuclear antibody (ANA) testing, as these help identify underlying causes of hair loss such as iron deficiency, thyroid disorders, autoimmune conditions, or hormonal imbalances 1. When evaluating alopecia, it is essential to consider the potential role of micronutrients, particularly vitamin D, zinc, and folate, which have been found to be lower in patients with alopecia areata compared to controls 1. Key points to consider in the laboratory workup for alopecia include:
- Serum vitamin D levels, as deficiency has been linked to several forms of alopecia, particularly alopecia areata 1
- Serum ferritin levels, which should ideally be above 50 ng/mL for optimal hair growth, as iron is essential for hair follicle function 1
- Thyroid function tests, as thyroid dysfunction can cause diffuse hair shedding 1
- Hormonal evaluation in women, including total and free testosterone, DHEAS, and prolactin levels, to determine if hyperandrogenism is contributing to the hair loss pattern 1 A scalp biopsy may be necessary in cases where the diagnosis remains unclear after initial testing 1. Early laboratory evaluation is crucial, as identifying and treating underlying medical conditions can often improve hair regrowth outcomes 1.
From the Research
Lab Work for Alopecia
Lab work for alopecia typically involves a range of tests to determine the underlying cause of hair loss. Some of the key tests include:
- Complete blood count (CBC) to evaluate inflammatory parameters and rule out underlying conditions such as iron deficiency or autoimmune disorders 2, 3
- Serum iron and ferritin levels to assess iron deficiency, which may be associated with alopecia areata 2
- Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to evaluate inflammation levels 3
- Scalp biopsy to diagnose cicatricial or noncicatricial alopecias 4, 5
Diagnostic Approaches
The diagnostic approach for alopecia involves a comprehensive clinical history and physical examination, as well as laboratory testing and scalp biopsy if indicated 4, 5. The ability to recognize and distinguish between different types of alopecia is crucial for providing adequate and timely treatment 6.
Inflammatory Markers
Recent studies have investigated the use of inflammatory markers such as red cell distribution width (RDW), mean platelet volume (MPV), plateletcrit (PCT), the ratio of neutrophils to lymphocytes (NLR), and the ratio of platelets to lymphocytes (PLR) in patients with alopecia areata 3. However, only CRP values were found to be significantly higher in patients with alopecia areata, suggesting its potential use as a diagnostic marker 3.