Transient Rectangular Alopecia after Endovascular Embolization: A Case Series of four Patients Describing Dermoscopic and Histopathologic Findings.

Transient rectangular alopecia after endovascular embolization (TRAEE) is considered a specific form of radiodermatitis that is probably underreported in the literature. We present a case series of four patients from our hospital describing dermoscopic and histopathologic findings. Dermoscopic findings overlap with those of alopecia areata; therefore, TRAAE may be misdiagnosed without a precise history. Histopathology analysis of one of our cases showed different characteristics from the only report in the literature (high proportion of follicles in telogen phase). Initial reports considered that total radiation doses between 3 and 5 Gy produced TRAEE, whereas doses higher than 7Gy could trigger permanent alopecia. However, one of our patients exposed to a total dose of 7.6 Gy had complete hair regrowth. Copyright:

INTRODUCTION

Endovascular neuroradiology procedures are rising in the last years; however, their cutaneous adverse effects are largely unknown and probably underreported.[1] Transient rectangular alopecia after endovascular embolization (TRAEE) was first described by Huda and Peters in 1994,[2] and only small case series have been published to date.[3456]

CASES REPORT

A 46-year-old woman presented at our department with a 1-month evolution asymptomatic alopecic patch in the right occipital area. As relevant medical history, she referred multiple sclerosis treated with interferon beta-1a. Furthermore, 17 days before appearance of the plaque, she had presented at the emergency department with an abrupt-onset severe headache. Computed tomography (CT) revealed a subarachnoid hemorrhage with a ruptured aneurysm in the anterior communicating artery (AcomA). A fluoroscopically guided embolization of the aneurysm was performed; the procedure duration was 85 min, and the total radiation dose was 7.6 Gy. One week later, she required ventriculoperitoneal shunting. During surgery, which lasted 150 min, she was in supine decubitus position with her head turned 45° to the right.

Physical examination revealed a rectangular, sharply demarcated, noncicatricial alopecic patch in the right occipital area [Figure 1a]. Trichoscopy findings included short villous hairs, broken hairs, black dots, and coiled hairs [Figure 2a]. With the diagnosis of TRAEE, she was prescribed 5% minoxidil topical solution, showing complete regrowth after 3 months.

Figure 1

Clinical image of the four patients showing sharply delineated rectangular alopecic patches. Patient 1 (a) presented one occipital patch, patient 3 (c) and 4 (d)presented one parietal patch and patient 2 (b) presented two different patches due to different consecutive fluoroscopy procedures

Figure 2

(a) Trichoscopy image of patient number 1 showing short villous hairs (yellow arrows), broken hairs (red asterisks), black dots (yellow asterisks), and coiled hairs (red arrow), (b) histopathology image (hematoxylin and eosin, magnification ×40) of patient number 2, showing a retracted, ascending hair follicle, leaving a fibrotic tail behind. These signs are consistent with telogen follicles, which were found in higher proportion, together with a slight, patchy, perivascular, and perifollicular lymphocytic infiltrate

After this case, we reviewed cases of postembolization alopecia seen in our dermatology department. We found three more cases between 2006 and 2016 [Table 1 and Figure 1b-d]. Including our case, there were two women and two men with a mean age of 46 years (27–60 years). The most frequently embolized artery was the AcomA, the mean latency time was 16 days, and all cases recovered completely. In one case (Case 2), a biopsy was performed 2 months after the appearance of the patch, showing a noncicatricial alopecia with increased proportion of telogen follicles and a slight, patchy, perivascular, and perifollicular lymphocytic infiltrate [Figure 2b].

Table 1

Characteristics of patients

Patient	1	2	3	4
Sex	Female	Male	Male	Female
Age (years)	46	27	50	60
Latency time (days)	17	7 and 21 (2 patches)	15	20
Location	Right occipital	Right occipital and vertex	Left parietotemporal	Frontoparietal
Embolized artery	AcomA	AcomA and bifurcation of ophthalmic artery with internal carotid artery	AcomA	AcomA
Trichoscopy	Short villous hairs, broken hairs, black dots, and coiled hairs	NK	NK	NK
Histology	NK	Noncicatricial alopecia with high proportion of telogen follicles	NK	NK

AcomA – Anterior communicating artery; NK – Not known

DISCUSSION

TRAEE is considered a specific form of radiodermatitis caused by an acute damage to the actively dividing matrix cells of the anagen hair follicles (anagen effluvium).[34] It usually presents 2–4 weeks after the procedure, as an alopecic patch of artifact morphology that resolves spontaneously after 12–14 weeks. Its appearance depends mainly on the total duration of the fluoroscopic procedure (especially after more than 100 min) and the total radiation dose, between 3 and 5 Gy. Initial reports considered that alopecia may become permanent with doses higher than 7 Gy. However, in our case, the radiation dose was 7.6 Gy, and some other cases of hair regrowth have been reported with higher doses up to 12 Gy.[47] Other factors, such as the pressure alopecia found in our patient or previous cumulative radiological procedures (i.e. CT scans), may also play a role.

Dermoscopy[8] and trichogram[9] findings overlap with those seen in alopecia areata; therefore, TRAEE may be misdiagnosed without a precise history.

In contrast with our case, the only histological analysis reported in the literature shows a high percentage of catagen follicles with no inflammatory infiltrate,[10] although differences in histology could depend, to a large extent, on the moment at which the biopsy was performed.

In summary, we present a series of four cases of TRAEE showing dermoscopy and trichoscopy findings. A correct diagnosis, essentially reached by a good anamnesis, is important to avoid unnecessary treatments and to reassure the patient.

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.