Diffuse hair loss can be due to a large number of factors that cause either physical or psychological stress, or to systemic diseases or external (usually pharmaceutical) agents. More specifically, the following have been reported as causes of diffuse alopecia:
- Physical stress, e.g. after major surgery, severe infection, high fever, acute bleeding. Also, many women experience diffuse alopecia after childbirth or even up to three months later, because of the abrupt changes in their hormone levels.
- Intense emotional stress, causing mostly acute diffuse alopecia.
- Chronic diseases such as anaemia, systemic lupus erythematosus, amyloidosis, liver failure, chronic renal failure, inflammatory bowel disease, lymphoproliferative syndrome, dermatomyositis, and other chronic infections such as HIV and secondary syphilis. Also, dermatological diseases such as psoriasis, seborrheic dermatitis and allergic contact dermatitis have been reported to cause diffuse telogen alopecia.
- Endocrine disorders. Both hyperthyroidism and hypothyroidism can cause diffuse telogen alopecia, which regresses when the person returns to a euthyroid condition, but also diabetes. Hair loss can also occur during menopause, due to hormonal changes.
- Eating habits. Inadequate intake of protein, iron, zinc, essential fatty acids and other nutrients, mainly due to exhaustive diets or eating disorders (e.g. anorexia) are among the most common causes, especially in women. Malabsorption syndromes and pancreatic diseases can also lead to diffuse alopecia. Equally dangerous are deficiencies of vitamin D and biotin.
- Medications such as oral contraceptives, androgens, retinoids for acne treatment, antithyroid drugs, some antidepressants, anticoagulants, vitamin A, some categories of heart drugs and some NSAIDs. Also, drugs used in chemotherapy for various cancers, which are cytotoxic, act on hairs in the anagen phase causing diffuse anagen alopecia.
- Radiation, which causes hair loss mainly in the affected regions. Radiation therapy, when done at low frequencies, has reversible effects on hair loss, with only a small change in the quality of the hair.
Diffuse alopecia is usually reversible and in a few months the hair thinning is being restored and hair follicles remain healthy. It is important, however, that the patient cooperates with the specialist dermatologist or plastic surgeon he/she consults, in order to identify the precipitating agent that caused hair loss, as the possibility of diffuse alopecia becoming chronic, or becoming a precursor to androgenetic alopecia still exists. In the latter case, the hair does grow back but the strands are weaker and thinner.
In the case of acute diffuse telogen alopecia, the cause must be identified; when the patient is isolated from the cause, the loss will stop instantly and the scalp will recuperate over a few months’ time. In the case of chronic diffuse telogen alopecia, things are more complicated, as its occurrence may be attributed to more than one factors. In both cases, a diet with adequate nutrients and protein must be followed. Administration of supplements, such as vitamin C which enhances the absorption of iron, vitamin B that has a suppressive effect on stress, biotin and zinc, can enhance the regrowth of hair.
If the cause is suspected to lie in some form of medication, it is recommended to change or stop the drug for at least three months, in order to confirm if this is indeed the precipitating factor. At the same time, the possible existence of an underlying disease is examined and it is controlled with proper treatment. There is no specific medication for the treatment of diffuse alopecia.
Anagen or dystrophic diffuse alopecia can be treated with monitoring and supportive treatment, especially if the cause is known from the patient’s history and cannot be avoided for a certain period of time. Especially, in cases of diffuse alopecia due to prior chemotherapy, in young men with a family history of androgenetic alopecia, it may be observed that the hair grows back after the end of chemotherapy, but only in areas that are not affected by androgenetic alopecia. In areas that are affected by the hereditary predisposition for androgenetic alopecia, the regrowth does not proceed satisfactorily, resulting in the appearance of clinically advanced androgenetic alopecia (grade V-VII on the Hamilton-Norwood scale) which normally would have only occurred several years later in the life of the individual concerned.
This advanced form of alopecia after chemotherapy can significantly burden the psychology of these patients and perhaps constitutes the only real indication for hair transplantation in situations of diffuse alopecia. In general, hair transplantation is not considered a treatment of choice in cases of recurrent diffuse alopecia. In any case, it requires examination by a specialist dermatologist or plastic surgeon, who will assess each case on an individual base.