Evaluation and Diagnosis
A detailed history and physical examination usually reveals the etiology of hair loss. A careful history should include the duration and pattern of hair loss, patient's diet, medication use, present and past medical conditions, family history and hair care practices. The following are few of the features typical of different types of alopecia which helps in their diagnosis:
- Prolonged shedding and thinning of scalp hair in the temporal and parietal areas, associated with a family history of common baldness, suggest AGA.
- Rapid and diffuse hair loss suggests anagen or telogen effluvium.
- A history of physical or psychologic stress, drug use, systemic disease, recent childbirth, crash dieting or other weight loss is also associated with telogen effluvium.
- Cold intolerance, irregular menses and constipation indicate alopecia secondary to hypothyroidism.
- Easy fatigability and palpitation may indicate alopecia secondary to anemia.
- Tight braids, ponytails, elastic hair bands, rollers or other devices that place extreme and repetitive stress on the scalp hair are responsible for most cases of traction alopecia.
- Tinea capitis and psoriatic alopecia should be considered in cases of scalp flaking.
- Chemotherapy or exposure to radiation cause anagen effluvium.
- Psychologic factors may be implicated in trichotillomania.
- ‘Moth eaten’ areas on the scalp suggest sarcoidosis, syphilis or discoid lupus.
The physical examination should focus on patterns of hair loss, inflammation, scarring and the condition of remaining hairs. The ‘hair-pull’ test helps to determine the ongoing activity of hair loss. Approximately 60 hairs are grasped between the thumb, index and middle fingers from the base and firmly but not forcefully pulled away from the scalp. If more than 6 hairs (10 percent) are pulled away, the hair loss is considered to be due to abnormal shedding but if the hair count is less than 6, it is taken as normal physiological shedding.
Laboratory tests to confirm alopecia include a complete blood count to detect infection and anemia, serology for lupus erythematosus, syphilis serology, thyroid profile for thyroid dysfunction and total testosterone and dehydroepiandrosterone sulfate for hair loss associated with androgen excess and hirsutism in women. Microbiologic studies are done to diagnose bacterial or fungal-induced alopecia.
Scalp biopsies help to make or confirm a diagnosis of alopecia and can be essential in guiding therapy. It is indicated in all cases of cicatrizing alopecias and unexplained non-cicatrizing alopecias.1
Written by: Healthplus24 team
Date last updated: March 24, 2009
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Articles in Alopecia