Diffuse alopecia is a condition characterised by a decrease in the hair density over the whole surface of the scalp. It may affect hair growth over the entire body, but is usually restricted to the scalp. 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. 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. Diffuse alopecia can affect women more than men.
Diffuse alopecia – Classification
Diffuse alopecia is a manifestation that, depending on the picture of the trichogram, may be due to:
- telogen effluvium, in which case the hairs prematurely and abruptly enter the telogen phase (the last stage of their life), while normally they should remain in the anagen phase for about three months, until the new hairs have developed, and then fall out.
- anagen or dystrophic alopecia, in which intense shedding of hair occurs (up to 90%) due to the effect of a chemical or toxic agent (e.g. chemotherapy) or radiation; the hair will grow back when the exposure to the agent is discontinued.
- mixed alopecia.
Also, depending on the length of time over which the hair is lost, it can be classified into:
- acute, with sudden loss of hair,
- subacute, in which the hair is lost over several of months
- chronic diffuse alopecia, in which the phase of thinning is repeated and overall lasts more than six months.
Diffuse alopecia – Causes
Diffuse alopecia arises as a result of a disruption of the normal life cycle of hair. 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.
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 – Treatment
Diffuse alopecia is usually reversible and in a few months the thinning of the scalp has been restored and the 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 try and identify the precipitating agent for the hair loss, as still exists a possibility that the diffuse alopecia will persist and become chronic, or become a precursor to androgenetic alopecia. In the latter case, the hair does grow back but the strands are weaker and thinner than before the strike of alopecia.
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, vitamins B that have 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 whether it is controlled with proper treatment.
There is no specific medication for the treatment of diffuse alopecia. Minoxidil solution of 2% or 5% topically on the scalp twice a day can help, especially in cases of chronic diffuse alopecia.
PRP (Platelet Rich Plasma) therapy has been tested in cases of diffuse alopecia and is currently used with excellent results, in combination with supportive treatment or medication. In this treatment, a small amount of the patient’s blood is obtained and centrifuged, activated by addition of calcium chloride, and then injected into the affected area, where it will release significant amounts of growth and healing factors, thus accelerating the process of hair regrowth. PRP therapy can be repeated at one month intervals, until the hair growth in the affected area is restored to a satisfactory degree. Each PRP session lasts about 30 to 45 minutes and does not require topical anaesthesia.
Also, in combination with conservative treatment, LLLT (Low Level Laser Therapy) can be used. The application of low-energy laser with mobile devices that can be used for home therapy, contributes to an increase of local blood supply to the affected area of the scalp, thereby improving the nutritional condition of the hair follicles and accelerating the development of new hair.
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 can not 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.