Cutis verticis gyrata induced by prolonged use of topical minoxidil at high doses

Abstract

Cutis verticis gyrata (CVG) is a rare condition affecting the scalp (SSC), which develops a spongy texture with folds and grooves on its surface. The number of folds can vary from two to more than 10, and they can range from occupying only a single region (central and posterior) to the entire surface of the SSC. It is classified as primary, essential, non-essential, and secondary. The underlying causes of the latter include acromegaly, elevated levels of growth hormone (GH), exogenous administration of GH, or other drugs that mimic its effects (secretagogues).

GH stimulates hepatic production of insulin-like growth factor (IGF-1), which in turn promotes bone and cartilage growth, soft tissue hypertrophy, visceromegaly, and hypertrichosis seen in acromegaly.

We present a 62-year-old patient with androgenetic alopecia who presented with GVC and was treated for 5 years with topical 10% minoxidil. MRI showed enlarged soft tissue and folds in the CC and ruled out pituitary gland abnormalities. Hormonal (GH, TSH) and blood glucose studies were normal, and a skin biopsy showed enlarged hair follicles and the associated arrector pili muscle. No other signs of acromegaly were observed. After discontinuing treatment, the patient experienced gradual reversal.

The authors stated that topical 10% minoxidil, although tested in some cases, is not approved by health authorities. It is described that minoxidil causes the opening of K+ channels with a mitogenic effect and enhances the effects of IGF-1, with the resulting follicular proliferation.

Furthermore, it is known to have effects on keratinocytes with cell proliferation and glycaesaminoglycan production, and in fibroblasts, it stimulates elastin synthesis and decreases the activity of the enzyme lysyl hydroxylase (key in collagenogenesis). Thus, minoxidil can remodel soft tissue in the skin with hyperplasia of the sebaceous follicle apparatus and adjacent tissues.

Finally, they collected information published in JAAD about a patient with pseudoacromegaly, including CVG, induced by high doses of oral minoxidil (due to hypertension), also with gradual reversal upon discontinuation. They concluded that it is important to monitor this adverse effect in patients receiving treatment with high-dose topical minoxidil for prolonged periods, and raised the need to inform the patient of this possible adverse effect and its reversibility upon discontinuation of the medication.