A New Era of Treatment for Rosacea

A New Era of Treatment for Rosacea: My Taiwan Experience

Jeng-Hsien LIN, Dr. LIN’s Dermatological Clinic, TAIWAN

Rosacea is a very complicated skin problem which is difficult to cope with. Even now, the drug that can result in quick improvement and long-term stabilization without recurrence is still lacking. The clinical subtypes include: erythrotelangiectatic rosacea (ETR), papulopustular rosacea(PPR), rhinophyma, and ocular rosacea. Among them, the former two types are the most common.

The clinical symptoms of rosacea is versatile, including persistent erythema on the cheeks, which is easily worsened by various exacerbating factors, such as sun exposure, excitement, nervousness, hot or spicy food, or alcoholic beverages. Recently, the treatment plan has shifted from targeting the different subtypes to aiming at different phenotypes.

In recent years, many studies have shown that the pathogenesis of rosacea is very sophisticated, including genes, immune systems, vascular hyper-responsiveness, nervous systems, skin barrier impairment, and demodex. The role of demodex in rosacea has been debated for a long time because they are the normal flora in human skin.

In Taiwan, Dr. Hui-Peng Huang, a rosacea expert, has been engaged in the relationship between rosacea and demodex for more than five years. He published two novel methods to more accurately exam the demodex density in ETR and PPR. The first one is “superficial needle-scraping method” when pustules are available.¹ The second one is “thumb squeezing method” when there is no pustules.² These two easier methods not only have much higher examination sensitivity (above 90%) when compared with previous standardized skin surface biopsy, but also confirm the pivotal role of demodex in pathogenesis of rosacea.

The recent advent of topical parasiticidal ivermectin ointment, in conjunction with the above-mentioned examination methods, has opened a new era in the diagnosis and treatment of rosacea. In fact, based on my experience of using topical ivermectin in the past two years, if the patients with demodex density can be correctly screened, the papules and pustules of rosacea can usually subside quickly within one month, and persistent erythema will also improve a lot (Figure 1). The demodex density can be lowered within normal limit In two to four months, and the clinical symptoms can be restored to a fairly good status. Moreover, the recurrence rate is much lower than the patients treated with traditional oral doxycycline and topical metronidazole gel. This is a huge leap forward for the traditional stereotype that rosacea is a disease with high recurrent rate.

A recent paper also found that the exacerbation of rosacea of some patients after intense pulsed light or pulse dye laser may also be related to demodex infection.³ It is presumed that when high-energy light penetrates the skin, demodex mites will be killed. The chitin exoskeletons and the bacteria or substances in the bodies of demodex can stimulate strong inflammation, which in turn causes flushing, erythema, papules and pustules, indicating worsening of rosacea. All these prove the importance of demodex in the pathogenesis of rosacea.

In conclusion, the great frustrations experienced by physicians in the treatment of rosacea in the past have undergone tremendous changes under the establishment of new concepts, the use of new examination methods, and the advent of new drugs. Combining the control of other pathogenic factors, treatment of rosacea is no longer so difficult, and the quality of life of patients can also be improved a lot.

Figure 1: Without any steroids, the topical anti-parasite ivermectin ointment can quickly improve severe rosacea in a few weeks.

References:

1.      A new superficial needle-scraping method for assessing Demodex density in papulopustular rosacea. J Cosmet Dermatol. 2019 Jul 25. doi: 10.1111/jocd.13082.

2.      Thumbnail-squeezing Method: An Effective Method for Assessing Demodex Density in Rosacea. J Eur Acad Dermatol Venereol. 2020 Mar 3. doi: 10.1111/jdv. 16321.

3.      Latent Demodex infection contributes to intense pulsed light aggravated rosacea: cases serial. J Cosmet Laser Ther. 2019;21(3):163-165.