Alopecia of Chemical Origin

Many chemicals, which are capable of inducing alopecia, are in frequent use in therapeutics. Man is only rarely and accidentally exposed to others. Together, they account for a small but increasing proportion of cases of diffuse alopecia. In many instances their mode of action is uncertain and a logical classification is therefore impracticable. Given below is description of the effects of some of the chemicals and homoeopathic remedies that can be used for the treatment.

Thallium

Thallium salts are no longer prescribed in Britain for the depilation of the scalp infected with ringworm, and are not contained in any preparation on sale to the public. In many other countries they are still used as pesticides, and serious outbreaks of poisoning have followed the contamination of grain stores and other food. Thallium salts are tasteless and have been used in homicide and suicide. Thallium is rapidly taken up by anagen follicles and disturbs keratinization. Many hairs break within the follicle; irregularity of the dark keratogenous zone and air bubbles within the shaft near the tapered tip give a distinctive appearance. Many other follicles enter catagen prematurely. Surface keratinization is also disturbed. Alopecia is the most constant symptom. The loss of hair begins after 10 days as diffuse shedding of abnormal anagen hairs. It may rapidly become complete or, with lower doses, may be followed by the gradual shedding of club hairs over a period of 3 or 4 months. In severe poisoning, death may result from acute cerebral and renal damage before hair loss can occur. In less severe cases the associated symptoms are very variable; ataxia, weakness, somnolence, tremor, headache, nausea and vomiting are among the most constant. In mild poisoning, alopecia may be the only symptom. In all cases the hair regrows completely within 6 months, but there may be persistent signs of residual cerebral damage. The diagnosis may be suspected on clinical grounds but can be confirmed only by the detection of the thallium in the urine and faeces in which it may continue to be excreted for 4 or 5 months.

Homoeopathic Remedies: Thallium, Plumbmum, Phosphorous

Thyroid Antagonists

Some patients with thyrotoxicosis treated with thiouracil or carbimazole develop a diffuse alopecia. Long continued administration of iodides has induced hypothyroid alopecia.

Homoeopathic Remedies: Thyrodinum, Iodum, Spongia

Anticoagulants

All the anticoagulant drugs (heparin, heparinoids and coumarins) will induce alopecia. Coumarins such as warfarin are widely used as rodent poisons and are sometimes accidentally ingested by children. The highest dose, and not the duration of the exposure, determines the degree of hair loss. Apparently normal club hairs are shed some 2-3 months after the effective blood level is achieved. There is often moderately increased shedding without obvious alopecia, but with high dosage moderate or severe alopecia may occur. Full recovery follows omission of the drug.

Homoeopathic Remedies: Phosphorous, Pulsatilla

Cytostatic Agents

Many cytostatic agents employed therapeutically or given with criminal intent can cause hair loss. Experimental and clinical studies with cyclophosphamide show that some anagen follicles enter catagen prematurely; in others the inhibition of mitosis in the matrix results in a constriction in the shaft or a complete break. A similar constriction is produced by aminopterin.

Clinically, alopecia is frequently observed after cyclophosphamide therapy. It has also been reported after therapeutic doses of colchicine, after an abortifacient dose of aminopterin and after cantharidin. Hairs with broken constricted shafts may be shed diffusely as early as 4-6 days after the first effective dose, and shedding of apparently normal telogen hairs may continue for some months.When cytostatic drugs are indicated, the expected loss of hair will be minimized by scalp hypothermia, e.g. applying ice packs to the scalp for 30 min before the drug is injected.

Homoeopathic Remedies: Pulsatilla, Sulphur, Cadmium Sulph

Triparanol

Triparanol, and the chemically unrelated antipsychotic drug fluorobutyrophenone, disturb keratinization by inhibiting cholesterol synthesis. Scalp and body hair becomes dry and sparse, and light in color. The skin is generally dry and ichthyotic. Cataracts develop later in some cases.

Homoeopathic Remedies: Phosphorous, Kali Phos, Nat Mur

Hypervitaminosis A

Excessive consumption of vitamin A gives rise to a variable syndrome in which the principal features are dryness, irritability and sometimes pigmentation of the skin, and slowly progressive thinning of scalp and body hair, eyebrows and eyelashes. Loss of weight, fatigue, anaemia and bone pain are frequent, and the liver and spleen are sometimes enlarged. The symptoms develop insidiously after doses in excess of 50 000 units daily have been ingested for many months. The mode of action of vitamin A on hair growth is unknown. Diagnosis is established by estimation of the fasting blood level of the vitamin. Slow recovery takes place when the vitamin A is discontinued.

Homoeopathic Remedies: Pulsatilla, Cal Phos

Boric acid

Occupational exposure to sodium borate has caused diffuse alopecia. Boric acid mouthwashes have caused a similar pattern of hair loss. Serum boric acid levels were elevated. Boric acid taken with suicidal intent caused total alopecia after 10 days.

Homoeopathic Remedies: Borax

Oral Contraceptives

Diffuse alopecia has been attributed to oral contraceptives. Studies of anagen-telogen counts showed a variable response: some women showed a temporary and some a more prolonged increase in telogen ratio, and in others no change was observed. In general, no clinically significant changes are induced, but in some women diffuse hair shedding follows 3-4 weeks after the contraceptive is discontinued, as after pregnancy; recovery occurs spontaneously.

Homoeopathic Remedies: Pulsatilla, Sepia, Cal Carb

Other chemicals

Irreversible alopecia is occasionally induced by other chemicals; potassium thiocyanate formerly prescribed for hypertension; trimethadione employed in the control of epilepsy; bismuth after prolonged over dosage; industrial exposure to the cyclic condensation products of monomeric chloroprene in the manufacture of rubber.

Other drugs described as inducing hair loss include lithium carbonate, pyridostigmine dixarazine and etretinate.
Propranolol metoprolol, levodopa and cimetidine have all been suspected of causing diffuse alopecia after several months of administration, as has ibuprofen.

The amino acid mimosine in Leucaena glauca and some other leguminous plants and the toxic substance in the nut Lecythus, which appears to be selenocystathionine, have also caused alopecia. Seleniferous plants are a well-known cause of hair loss in cattle, and there are occasional reports of a similar effect in man.

There are many anecdotal and unsubstantiated cases of alopecia thought to be related to specific drugs amiodorone, cimetidine, danazol, gentamicin, itraconazole, metyrapone, pyridostigmine, sulphasalazine and terfenadine.

01 Feb 2010