Diffuse alopecia is essentially due to a disruption of the normal evolution of the life cycle of hair, usually under the influence of some harmful agent. This causes ‛immature’ hairs to suddenly pass into the shedding phase; during this period, an overall thinning of the scalp is observed, with no specific areas of hair loss. It may affect hair growth over the entire body but is usually restricted to the scalp.
Usually, after a period of 3-4 months or when the effect of the harmful agent ceases to exist, the phenomenon subsides and the thinning is restored. It is often hard to diagnose because the thinning is observed several (usually 3-4) months after the effect of the possible cause, which in most cases is no longer present in the patient at that time.
Which are the causes of Diffuse Alopecia?
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.
How is Diffuse Alopecia being treated?
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 factor. 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.