**11. Physical examination**

The scalp hair and scalp skin should be carefully examined in all patients. Scale, inflammation, pustules, and scarring or abnormalities of the hair shaft should not be evaluated as the manifestations of an isolated TE. On physical examination, the entire skin surface should be examined to identify the extent of hair loss and to detect the main features of other hair or scalp disorders [10].

#### **11.1. Hair pull test**

**10. Laboratory**

132 Hair and Scalp Disorders

results [20, 25–27].

are observed [2].

disease research laboratory test is recommended [1].

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

not been established in all cases [27, 28].

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

Hypolipidemic drugs Venlafaxine Cetirizine Vinblastine Gold Vincristine

**More than 5%: 1–5%: Less than 1%** Mood stabilizers (lithium and valproic acid): *the most common* Oral contraceptives Amiodarone Antidepresants (fluoxetine) Acyclovir Amitriptyline Oral retinoids (acitretin, isotretinoin) Allopurinol Azathioprine Anticoagulant (heparin,enoxaparine, warfarin) Buspirone Dopamine Antimicrobial (isoniazid) Captopril Naproxen Antiviral (indinavir) Carbamazepine Omeprazole Interferon alpha Cyclosporine Paroxetine Terbinafine Lamotrigine Sertraline Beta-blockers (metaprolol, propronolol) Nifedipine Verapamile

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

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

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 A hair pull test should be performed as part of the physical examination in patients with suspected TE. The test is helpful to detect active hair shedding. About 50–60 hair fibers close to the skin surface are grasped and the hairs from the proximal to distal ends are tugged. Normally, only two or three hairs are pulled out by this method. In the presence of abnormal shedding, more than 10% hair (6–10 hair) can be easily pulled out from any part of the scalp, if the patient has not shampooed for more than 24 h [2, 30]. The test should be performed in four regions of the scalp: the frontal, occipital, and both temporal regions. The hair should not be shampooed for at least a day [29]. Light microscope is used to examine the hair shafts and to confirm that the loose hairs are telogen hairs [10].

Of note, the hair pull test may produce a false-negative result, if the patient has shampooed or vigorously groomed the hair on admission. In addition, if the patient has not shampooed or combed the hair for several days, the test may yield false positivity [10].

#### **11.2. Trichogram (hair pluck test)**

From a hair pluck, sample is abnormal, which indicates higher than 25% telogen hair [13]. Since telogen rate in this test is not associated with the severity of the hair loss, the sensitivity of the hair pull test is low [2].

#### **11.3. Wash test**

As daily hair count is troublesome, the wash test has been proposed. In wash test, the patient is instructed to wash hair after 5 days of last shampoo in a sink with its drain covered by gauze. The hair entrapped in the gauze is, then, counted [2].

#### **11.4. Dermoscopy**

Data relating to the dermoscopic findings of TE are limited. Acute TE may indicate empty follicles and regrowing hairs of normal thickness (>0.03 mm). Dermoscopic findings are useful to distinguish chronic TE from female pattern hair loss (female androgenetic alopecia). The latter variably exhibits a greater hair diameter [31].

#### **11.5. Wood's light examination**

TE can be due to seborrheic dermatitis of the scalp. On physical examination, a greasy scale and erythema on the scalp can be seen with a characteristic distribution. In addition, examination with a Wood's lamp (a source of ultraviolet A light) can be useful for the definite diagnosis of seborrheic dermatitis, which unveils the scale [32].

#### **11.6. Procedures**

In the majority of cases, further investigation is not required, beyond the clinical history and physical examination. However, additional diagnostic tools can be useful in patients in whom the diagnosis remains unclear [10].

#### **11.7. Scalp biopsy**

In most cases, scalp biopsies are not required and are only reserved for certain patients with an obscure diagnosis. Although scalp biopsy is not mandatory, it helps to exclude female pattern hair loss and alopecia areata. In general, biopsy results are normal, except increased telogen follicles (normal telogen counts vary between 6 and 13%). The rate of telogen follicles more than 15% indicates TE, while more than 25% is the major manifestation of TE [2, 30].

A 4-mm punch biopsy is sectioned horizontally for each specimen, and a second specimen is sectioned vertically. In general, we perform biopsy in an area outside of predilection for androgenetic alopecia to reduce the possibility of diagnostic uncertainty; therefore, we avoid bitemporal, frontal, and vertex areas of the scalp, if applicable. We usually select the leading edge of the alopecic area and avoid completely bald areas [10].

#### **11.8. Trichograms and phototrichograms**

Although these techniques are less common, they may be helpful to confirm the diagnosis of TE. With the use of these techniques, the rate of telogen and anagen hair follicles on the scalp can be evaluated. Currently, trichograms and phototrichograms are mostly used in specialized clinical hair centers and research studies. These procedures are described in detail in a separate section [10].
