Coupled Blue and Red Light-emitting Diodes Therapy Efficacy in Patients With Rosacea

Two Case Reports

Elisabetta Sorbellini; Maria Pia De Padova; Fabio Rinaldi


J Med Case Reports. 2020;14(22) 

In This Article


Acne rosacea, usually referred to as rosacea, is a common inflammatory skin condition affecting mainly the central face.[1] The term was introduced by Thomas Bateman in the nineteenth century as an acne variety.[2] Its typical manifestations are generalized erythema, telangiectasia, and edema, then papules and pustules or a combination of all.[3,4]

In 2004, the National Rosacea Society (NRS) Expert Committee published a report on the classification and staging of rosacea that defined the criteria for rosacea classification and grading according to primary and secondary descriptors.[5] Four subtypes of rosacea can be recognized on the basis of different morphological characteristics: erythematotelangiectatic, papulopustular, phymatous, and ocular.[5,6] The erythematotelangiectatic subtype is the most common one followed by papulopustular, phymatous and ocular types which are reported as less common.[7] Data from clinical practice show that patients often can harbor more than one rosacea subtype;[7] for this reason, incidence and prevalence evaluation is not simple. The latest data population, based on published data, refers to an incidence of 1.65 per 1000 persons per year[8] indicating approximately 5.46% of the worldwide population.[9] A stronger predominance for females was found for erythematotelangiectatic and papulopustular subtypes with a diagnosis, usually, after the fourth decade of life.[8,10]

The exact pathogenesis of rosacea remains unclear but the involvement of several external or endogenous factors is reported.[1,11] In fact, recent findings highlighted the role of predisposing factors such as genetic predisposition and association with other diseases.[12] Microbial stimuli, especially colonization, ultraviolet (UV) radiation, stress, and environmental changes are also recognized as triggering factors both for the development and worsening of rosacea.[12–14] Therefore, dysregulation of innate immunity via the expression of higher amounts of toll-like receptor 2 (TLR2) in the skin[15] and augmentation of the inflammatory cascade have been reported[16] as abnormal expression of cathelicidin antimicrobial peptides.[17]

More recently, rosacea and other skin diseases such as psoriasis and atopic dermatitis have been linked to intestinal dysbiosis.[18,19] Authors reported the role of intestinal dysbiosis in promoting inflammation and impairment of normal lymphocyte function, potentially perpetuating chronic, low-grade inflammation.[20] Therefore, the potential role of microorganisms in the pathogenesis of rosacea has been hypothesized.[21] Parodi and colleagues[22] reported a higher incidence of small intestinal bacterial overgrowth (SIBO) when patients with rosacea were compared to controls. Most interesting, microbial unbalancing of the skin microbiota on the skin has been linked to rosacea clinical manifestations,[23] even though the direct correlation between microbiota composition on the skin and the incidence of the pathology is still under investigation.

More recently, in a NRS-supported study in twins, Zaidi and colleagues[24] reported the first evidence highlighting the correlation between the severity of rosacea and microbial dysbiosis on the skin, but further study is needed to determine the species involved.

Historically, therapeutic approaches to rosacea focused on symptom suppression by means of anti-inflammatory agents such as doxycycline,[25–27] metronidazole,[28] topical azelaic acid,[11,29] sodium sulfacetamide,[11,30] and calcineurin inhibitors.[31] The use of serine protease inhibitors is to be considered an emerging therapy in rosacea.[32]

Several concerns surround the use of tetracyclines, especially as long-term treatment is often necessary. Although it is commonly prescribed at a sub-antimicrobial dose, gastrointestinal side effects and photosensitivity are not uncommon and the risk of antimicrobial resistance increases with higher doses.[33,34]

Although not yet approved for the treatment of rosacea, efficacy of a low dose of isotretinoin has been reported in patients with papulopustular rosacea subtype.[35]

More recently, photodynamic therapy (PDT), especially light-emitting diodes (LED), has been introduced as a valid alternative to conventional therapy.[36] A few in vitro studies[37,38] and a published in vivo study on patients with papulopustular rosacea with methyl ester aminolevulinate (MAL) coupled with PDT,[39] reported efficacy of LEDs for treatment of rosacea.