Hair growth disorders drug-induced

The disturbances or changes of the hair under the influence of systemically effective drugs affect the hair growth on the one hand and the hair texture on the other hand. The following changes are known:

Changes in the hair texture

• Trichomegaly: Trichomegaly is possible as a monosymptomatic (monotopic) variant or as part of a generalized hypertrichosis. Trichomegaly of the eyelashes has been described as an undesirable side effect of alpha-interferon, ciclosporin A and lanataprost in topical glaucoma treatment (see also eyelash lengthening by prostaglandin analogues). Not infrequently (a reversible) trichomegaly of the eyelashes occurs under the EGF-receptor blocker cetuximab after 3-6 months of therapy (Koksal UI et al. 2016). The combination of trichomegaly and poliosis was also described under cetuximab (Goyal S et al. 2018).
• Acquired frizzy hair: Acquired frizzy hair (hair curl) may occur in connection with the ingestion of various drugs. medications. These include: alitretinoin, tretinate, isotretinoin, valproic acid, indinavir, EGFR tyrosinase inhibitors (gefitinib, erlotinib). Hair crimping is still a phenomenon observed in regrowing hair after cytostatic therapy.

Changes in hair colour

• hair whitening: mephenesine, triparanol, butyrophenone, haloperidol, bleomycin, chloroquine, hydroxychloroquine -s.u. Canities, medicinal
• Darker hair: Diazoxide, Minoxidil (only available as topical drug!).
• Graying of the hair: Mephenesin, Triparanol, Butyrophenone, Haloperidol, Bleomycin.

Drug-induced hair loss (Effluvium/Alopecia)

Drugs can cause 3 types of hair loss: telogenic effluvium, anagenic effluvium

• Telogenes-Effluvium is the most common form of hair loss associated with medication. The hair loss usually occurs within 2-4 months after taking the medication. As a result, the hair follicles go through a resting phase (telogen) and fall out prematurely.
• Anagenes Effluvium: Anagenes Effluvium is the hair loss that occurs during the anagen phase, the active phase of the hair cycle. This type of hair loss usually occurs within a few days to weeks after taking the medicine. Chemotherapeutic drugs are the most common cause of drug-induced hair loss. The severity of drug-induced hair loss depends on the type of medication, its dosage and the sensitivity of the person concerned to the medication. The following medications can cause an anagen effluvium, some of them more or less obligatory:
  • Retinoids, antibiotics and antifungals, antidepressants, contraceptives (birth control pills), ovulation triggers (clomiphene), anticoagulants (coumarin), cholesterol-lowering drugs, immunosuppressants, Chemotherapeutic drugs, anticonvulsants, anti-hypertensive drugs, antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), Parkinson's drugs, glucocorticoids, thyrostatic drugs, weight loss drugs.
  • Chemotherapeutic drugs usually (almost obligatory) cause an anagenic effluvium, caused by toxic damage to the hair matrix cells. The effluvium generally sets in 2 weeks after the start of chemotherapy and increases after 1-2 months. The following chemotherapeutic drugs cause anagenic hair loss: Adriamycin, cyclophosphamide, dactinomycin, daunorubicin, docetaxel, doxorubicin, etoposide, fluorouracil, irinotecan, methotrexate, nitrosoureas, paclitaxel, tamoxifen, topotecan, vinorelbine.
  • PD-1 inhibitors cause alopecia areata in individual cases ( Guidry J et al. 2018)

Hypertrichosis

• These drugs cause hypertrichosis: Ciclosporin, Minoxidil, Glucocorticoids, Phenytoin

Hirsutism

• Hirsutism can be caused by the following drugs: testosterone, danazol, ACTH, metyrapon, anabolic steroids

How is drug-induced hair loss diagnosed and treated? It is important to know the medications that cause hair loss. If the hair loss occurs after taking a medication, it is very likely that it will stop after stopping the medication. With hair loss, which is almost obligatory under certain chemotherapeutic drugs, scalp cooling can reduce the effluvium (Shah VV et al. 2018). A few minutes before chemotherapy, ice packs are placed on the scalp. The cooling of the scalp reduces the blood flow to the hair roots, making it difficult for the chemotherapeutic agent to reach the follicle cells. The efficiency of this procedure is stated to be 50-80% (Rubio-Gonzalez B et al. 2018). After chemotherapy treatment, the hair usually grows back quickly. In rare cases, the hair may be thinner or even wavy after the treatment. Minoxidil (originally used as an antihypertensive, the hypertrichosis under Minoxidil was reported as a side effect) may be helpful.

1. Goyal S et al (2018) Epidermal growth factor receptor inhibitor induced trichomegaly and poliosis. Ophthalmology 125:294.
   Guidry J et al (2018) PD-1 inhibitor induced alopecia areata. DermatolOnline J 24:13030.
2. Koksal UI et al (2016) Trichomegaly Induced by Cetuximab: Case Series and Review the Literature. Am J Ther 23:e1226-1229.
   Rubio-Gonzalez B et al. (2018) Pathogenesis and treatment options for chemotherapy-induced alopecia: a systematic review. Int J Dermatol 57:1417-1424.
3. Shah VV et al. (2018) Scalp hypothermia as a preventative measure for chemotherapy-induced alopecia: a review of controlled clinical trials. J Eur Acad Dermatol Venereol 32:720-734.
4. Tosi A et al. (1994) Drug-induced hair loss and hair growth. Incidence, management and avoidance. Drug Saf 10:310-317.