Short-Term Topical Minoxidil Use Associated with Acute Central Serous Chorioretinopathy: A Case Report

Abstract

Introduction

Minoxidil is a topical, over-the-counter, FDA-approved drug used to treat male and female pattern hair loss. Three case reports were published associating long-term use of topical minoxidil to central serous chorioretinopathy (CSCR) after 4, 6, and 8 months of use. In this report, we will present a case of CSCR after 1 week of topical minoxidil use that resolved with discontinuation of medication and observation 6 weeks later.

Case Presentation

A 34-year-old Hispanic male presented with a 2-week history of central visual loss and flashes in the left eye. His only medication use was 5% topical minoxidil foam for hair loss, which he had started 1 week prior to symptom onset. Ophthalmic exam revealed a round elevation of parafoveal region of the left macula with optical coherence tomography evidence of subretinal fluid and an inferior pigmented epithelial detachment, consistent with CSCR. Given recent initiation of topical minoxidil, we suspected that minoxidil may have induced CSCR. Topical minoxidil was discontinued with recommended observation. There was complete resolution of CSCR at 6-week follow-up.

Conclusion

Subacute, unilateral central visual loss in an otherwise healthy 34-year-old male was found to be caused by minoxidil-induced CSCR. The correlation of topical minoxidil use 1 week prior to symptom onset with resolution of findings 6 weeks after discontinuing the medication suggests CSCR as a side effect of topical minoxidil. This case report suggests that short-term use of topical minoxidil, as short as 1 week, can induce CSCR. Our case shows that minoxidil-induced CSCR can be managed with medication discontinuation and observation.

Introduction

Minoxidil is a topical, over-the-counter, FDA-approved drug used to treat male and female pattern hair loss, also known as androgenetic alopecia. Originally, the oral formulation of minoxidil was used to treat hypertension. A common side effect of this medication was hypertrichosis, and clinicians began to prescribe topical minoxidil for hair loss [1]. The mechanism of action is thought to work through several pathways including vasodilation, anti-inflammatory, anti-androgen, promotion of DNA synthesis, and induction of the Wnt/β-catenin pathway by stimulating release of vascular endothelial growth factors (VEGFs) [1]. Further research on the Wnt/β-catenin pathway showed that minoxidil stimulates release of VEGF to promote angiogenesis and maintain vascularization of the dermal papilla [2].

Topical minoxidil used for hair loss comes in two formulations, foam (5%) and solution (2% or 5%). Both formulations are intended to be used daily with peak hair growth after 1 year [1]. Postmarketing side effects include allergic contact dermatitis, pruritus, application site reaction, and central serous chorioretinopathy (CSCR) [3]. Three case reports were published associating long-term use of topical minoxidil to CSCR after 4, 6, and 8 months of daily use [4–6]. In this report, we will present a case of CSCR after 1 week of topical minoxidil use that resolved with discontinuation of medication and observation 6 weeks later.

Case Presentation

A 34-year-old Hispanic male with past ocular history of LASIK surgery in both eyes presented to our retina clinic with a 2-week history of central visual loss in the left eye. The patient stated he woke up with a black spot in the center of his vision one morning 2 weeks ago without any preceding events. The central visual loss was constant and without change since onset. He did note intermittent flashes of light in the left eye only. He denied any associated floaters, metamorphopsias, or changes in stress levels. He denied any recent use of oral steroids or use of steroid injections, creams, nasal sprays, and inhalers. He denied any medication use except for the use of topical minoxidil (Rogaine, Johnson and Johnson) for hair loss. He started using topical minoxidil 5% foam approximately 1 week before the onset of his visual disturbance. The use of minoxidil was ½ capful of 5% foam applied twice daily to the area of hair thinning, located at the vertex of the scalp in this patient. This area of the scalp was normal in appearance and not dry, fissured, or actively inflamed at the time of application.

On exam, his best corrected visual acuity was 20/40 in the right eye and 20/60 in the left eye. Intraocular pressure was 10 mm Hg in the right eye and 16 mm Hg in the left eye. Extraocular muscle testing was full. Confrontational fields revealed a small central scotoma of the left eye. Pupils were 4 mm in dark, constricting to 3 mm in the light. No relative afferent pupillary defect was noted. Anterior exam was unremarkable in both eyes. Dilated fundus exam revealed a cup to disc ratio of 0.3, clear vitreous, normal appearing vessels, and intact peripheral retina in both eyes. Macula was flat and attached in the right eye. In the left macula, there was a round elevation of the parafoveal region without associated hemorrhage or exudate. Optical coherence tomography (OCT) of the right macula revealed a normal foveal contour with no intra-retinal or subretinal fluid. OCT of the left macula revealed an abnormal foveal contour with subretinal fluid and an inferior pigmented epithelial detachment (PED). There was no obvious choroidal thickening, but a bulge in the nasal retinal pigmented epithelium (RPE) posterior to the subretinal fluid was present (Fig. 1). RPE bulge has been shown to be a characteristic finding of CSCR on OCT macula [7]. Unfortunately, enhanced depth imaging with OCT of the choroid and fluorescein angiography could not be performed at this visit.

Fig. 1.

OCT macula of left eye showing suspected minoxidil-induced CSCR and 6-week follow-up after discontinuing the medication. Image a was obtained at the first office visit. Left macula had subretinal fluid and an inferior PED (PED not shown in this image). There was no obvious choroidal thickening, but there was a bulge in the nasal retinal pigmented epithelium (RPE) posterior to the subretinal fluid suggestive of CSCR. Image b was obtained at 6-week follow-up after discontinuing topical minoxidil. Left macula showed complete resolution of subretinal fluid and inferior PED.

The findings of subacute, unilateral, central visual loss in a 34-year-old male with OCT evidence of subretinal fluid, PED, and RPE bulge are consistent with CSCR. Given his recent initiation of topical minoxidil 1 week ago and no other obvious etiology to cause CSCR, we suspected that minoxidil may be the underlying cause of his pathology. Therefore, we recommended discontinuing topical minoxidil. We also educated the patient to reduce stress as much as possible, observe without medical therapy, and follow up in 6 weeks.

The patient returned to our clinic 6 weeks later with complete resolution of symptoms. He denied any ongoing central visual loss or flashes of light. His visual acuity improved to 20/50 in the left eye. OCT of the left macula showed complete resolution of subretinal fluid and inferior PED (Fig. 1). He has not used his topical minoxidil since the last office visit. Given resolution of CSCR, we recommended that he continue not using his topical minoxidil and a follow-up in 3 months for repeat dilated fundus exam and OCT macula.

Discussion

Topical minoxidil is thought to work through multiple different mechanisms of action to promote hair growth in the setting of androgenetic alopecia. Several hypotheses have been introduced to explain minoxidil-induced CSCR, including choroidal vasodilation [6], inhibition of RPE proliferation [8], and increased choroidal vascular permeability by simulating VEGF release [6]. CSCR induced by topical minoxidil has been reported but only in case reports and with long-term daily use ranging from 4 to 8 months [4–6]. Previous studies have shown a type C adverse drug reaction, known as dose-related or time-related, where prolonged use of topical minoxidil leads to CSCR. However, our case report of short-term topical minoxidil use suggests a type B adverse drug reaction, known as non-dose-related, leading to CSCR. Explanations to why this patient had a type B adverse drug reaction are hard to confidently determine but include two possibilities. First, this could have been an immune or inflammatory hypersensitivity to the medication. Second, this could have been an idiosyncratic reaction arising from genetic variations. Either a hypersensitive or idiosyncratic reaction from topical minoxidil led to a type B adverse drug reaction inducing acute CSCR after 1 week of use which is unique compared to the other case reports which highlighted choric use leading to CSCR.

Minoxidil has also been associated with other rare ophthalmic vascular side effects, such as: retinal artery occlusion [9], retinal vein occlusion [10], and non-arteritic ischemic optic neuropathy [11]. These known cases of other vascular side effects further strengthen the argument that underlying vascular changes could be the underlying mechanism of CSCR and underscore the spectrum of the vascular side effect profile of minoxidil.

Subacute, unilateral central visual loss in an otherwise healthy 34-year-old male was found to be caused by minoxidil-induced CSCR. The patient was not taking any other medications at the time and did not experience any changes to major life stressors. The correlation of topical minoxidil use 1 week prior to symptom onset with resolution of findings 6 weeks after discontinuing the medication suggests CSCR as a side effect of topical minoxidil. Interestingly, only long-term use of minoxidil was previously documented to induce CSCR. This case report suggests that short-term use of topical minoxidil, as short as 1 week, can also induce CSCR. Our case shows that minoxidil-induced CSCR can be managed with medication discontinuation and observation.

Shortcomings of this case report were lack of multiple imaging modalities to confirm diagnosis of CSCR. Enhanced depth imaging-OCT and fluorescein angiography would have been helpful in more strongly confirming the diagnosis of CSCR.

Further research is needed to identify the rate of minoxidil-induced CSCR to properly educate the public and other healthcare providers on risks of taking this over-the-counter medication. Further studies should also be aimed to evaluate if there is a need for standardized screening in patients taking this medication.

Statement of Ethics

This retrospective review of patient data did not require ethical approval in accordance with local/national guidelines. Written informed consent was obtained from the patient for publication of the details of their medical case and accompanying images. A CARE checklist is provided as supplementary material (for all online suppl. material, see https://doi.org/10.1159/000548230).

Conflict of Interest Statement

The authors have no conflicts of interest to declare.

Funding Sources

This study was not supported by any sponsor or funder.

Author Contributions

Jacob Brucker: writing of the manuscript. Brian Mihok: editing and revision of the manuscript. Jeffrey Bloom: conceived the presented idea and contributed to editing and revision of the manuscript.

Funding Statement

This study was not supported by any sponsor or funder.

Data Availability Statement

All data generated and analyzed within this article are included within the article. Further inquiries can be directed to the corresponding author.