Eyebrow Whitening Induced by Imatinib.

Sir,

Imatinib is a proven tyrosine kinase inhibitor (TKI) widely used for the treatment of chronic myeloid leukemia (CML). It is a rationally designed oral signal transduction inhibitor that specifically targets several protein tyrosine kinases: Abl, Arg (Abl-related gene), the stem cell factor (SCF) receptor (c-KIT), platelet-derived growth factor receptor, and their oncogenic forms, most notably bcr-abl. Its well-known adverse effects are hematological (cytopenia), edema, myalgia, electrolyte disturbances, and rash.[1] There has been reported a case with eyebrow whitening induced by dasatinib, another TKI.[2] Here, we present the first case of eyebrow whitening induced by imatinib in literature, based on our experience.

A 56-year-old female patient was prescribed imatinib 400 mg/day for chronic-phase CML 1 year ago in our clinic. She had the diagnosis 3 years ago from another center and was using imatinib for 3 years. We discovered progressive eyebrow whitening for the last 3 months [Figure 1]. Ten to twelve hairs of whitening was counted bilaterally; it was <2/3rd of the total eyebrow mass and evaluated as Level 2 (according to the Eyebrow Whitening Scale: Level 0: no whitening; Level 1: 1–3 strands; Level 2: between 3 and 10 strands, Level 3: 11 strands and 2/3rd of whitening, level 4: whitening of 3/4th or more strands).[3] There was no previous trichoscopic image, so no comparison could be performed. There were no other depigmented body hairs detected. There was no particular feature at her own medical or family history. Her CML was on complete remission, and her blood count, iron, Vitamin B12, zinc, and thyroid-stimulating hormone levels were completely normal. She did not complain of her eyebrow whitening, and so the TKI treatment was continued.

Figure 1

The picture of eyebrow whitening of the patient (patient consent has been obtained)

Sunitinib is a a vascular endothelial growth factor receptor multikinase inhibitor and usually used for the treatment of metastatic renal cell carcinoma.A case of eyebrow whitening, possibly because of using sunitinib is defined in the literature. It was emphasized that the etiology is unclear for hair depigmentation.[4] Hair depigmentation has been shown to occur with disruption of the interaction between the ligand SCF and its Class III receptor tyrosine kinase c-KIT, also called the SCF receptor. Both dasatinib and sunitib usage was associated with hair depigmentation, so similar mechanism may be responsible for imatinib.

Clinicians should be aware of eyebrow whitening when using TKIs such as imatinib.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.