**9. Evaluation**

Patients with TE should be evaluated with a detailed history, physical examination, and laboratory tests (**Table 3**) [1]. In addition, TE subtype, duration, and clinical course of hair loss should be also questioned. In particular, possible triggering factors within 2–5 months before hair loss begins should be addressed [7]. In the absence of no causative factor, a complete blood count, serum ferritin, biochemical markers, and thyroid function tests should be performed [2].

In addition, hair-care practices of patients which may damage hair such as braiding leading to traction alopecia, and the loss of eyelashes, eyebrows, and axillary, pubic, or body hair should be questioned, as alopecia areata or trichotillomania may affect any hair-bearing area. A detailed history, childbirth, prior surgeries, and psychosocial stress should be also assessed. Furthermore, drugs that may cause TE should be examined (**Table 4**) [1, 2]. Additionally, acne, irregular menstrual cycles, or hirsutism may indicate androgen excess, which contributes to female pattern hair loss. Symptoms of hyperthyroidism or hypothyroidism should be also evaluated and current and previous medications should be carefully reviewed. A history of following a strict vegetarian diet or heavy menses may suggest iron deficiency anemia [1].


**Table 3.** History of hair loss checklist [1].


**Table 4.** Drugs associated with telogen effluvium [1, 2].

### **10. Laboratory**

Although the majority of female patients with hair loss have normal laboratory test results, a complete blood count, ferritin, thyroid-stimulating hormone, antinuclear antibody titer, and vitamin D level can be studied, as abnormal levels of these parameters are likely to be associated with distinct forms of alopecia. In addition, serum and free testosterone, dehydroepiandrosterone sulfate, and prolactin should be analyzed, in the presence of any signs of potential endocrine abnormalities including severe acne, hirsutism, virilization, galactorrhea, menstrual irregularities, or infertility [14]. In case of any risk factors for syphilis, the venereal disease research laboratory test is recommended [1].

The link between serum levels of ferritin or vitamin D and TE is controversial. To date, studies investigating the relationship between serum ferritin levels and TE have shown controversial results [20, 25–27].

Iron deficiency anemia and thyroid disorders are the common conditions associated with TE. However, in the majority of cases, no apparent clinical features suggesting these conditions are observed [2].

A strict vegetarian diet or heavy menses may be suggestive for iron-deficiency anemia. Iron supplementation is recommended for TE patients who have had a serum ferritin level less than 70 ng per milliliter [20]. However, the effects of iron supplementation for TE have not been extensively investigated in controlled trials. The efficacy data are limited to case series, indicating cessation of hair loss and new hair growth with iron supplementation in women with low ferritin levels. On the other hand, the beneficiary effect of iron supplementation has not been established in all cases [27, 28].

Furthermore, perimenopausal symptoms such as hot flashes and irregular bleeding should be evaluated in older women. In this age group, starting or interrupting hormonal replacement therapies should be ruled out as a possible cause of TE [29].
