Foods that Trigger Rosacea Flare-Ups

Introduction

Rosacea is a skin condition that generally appears on the central face and is characterized by flushing, erythema, edema, pustules, papules, ocular lesions, and other related skin symptoms.^[1] A typical patient does not usually exhibit all cutaneous symptoms, but rather expresses only some of the signs.^[1] There is some evidence that modifiable lifestyle factors, such as diet, can have an impact on rosacea as specific types of food and beverages have been shown to act as triggers for rosacea. They can be broken down into categories such as heat-related, alcohol-related, capsaicin-related, and cinnamaldehyde-related triggers.^[2] One proposed mechanism on how food may trigger a rosacea exacerbation is through the activation of transient receptor potential cation channels (TRP).^[2]Activation of these channels may lead to neurogenic vasodilation.^[2]

There is some evidence that modifiable lifestyle factors, such as diet, can have an impact on rosacea as specific types of food and beverages have been shown to act as triggers for rosacea. They can be broken down into categories such as heat-related, alcohol-related, capsaicin-related, and cinnamaldehyde-related triggers.^[2] One proposed mechanism on how food may trigger a rosacea exacerbation is through the activation of transient receptor potential cation channels (TRP).^[2]Activation of these channels may lead to neurogenic vasodilation.^[2]

Food Triggers for Rosacea

Certain foods and beverages can trigger a rosacea flare-up, so patients may need to be counseled to alter their diets in order to avoid certain triggers. While other foods such as dairy and chocolate can cause flares, spices seem to be compounds that trigger flare-ups the most.

Channels and Rosacea

The TRP superfamily is a family of cation channels that have important roles in sensory physiology.[7] The TRP channels are expressed in neuronal and non-neuronal tissues throughout the body.[8]There are 2 subfamilies within this family of transient receptor potential cation channels that have been thought to contribute to rosacea’s pathogenesis due their ability to mediate sensory and inflammatory signaling.^[9]

Group 1 TRP’S

• TRPC
• TRPV
• TRPM
• TRPN
• TRPA

Group 2 TRP’S

• TRPP
• TRPML

Evidence shows that TRP channels are increased in rosacea and that activation of these channels plays a role in the pathogenesis of rosacea due to their effect on neurogenic vasodilation.^[10]

TRPV 1, TRPV 2, TRPV 3, TRPV 4 and TRPA 1 have all been shown to be involved in the inflammatory process in rosacea.^[11] TRPV1 is found in many places in the body such as in keratinocytes and free nociceptive sensory nerve endings. Patients with rosacea have an abnormal response to heat, exercise, stress, and spices with the response being mediated by TRPV1 that can present as flushing and stinging.^[11] It has been found that TRPV 3 is responsible for vasodilation via nitrous oxide (NO), in addition, TRPV 4 and TRPA 1 are also involved in vasodilation.^[11]

Table 3. Relationship between different types of rosacea and TRPV ion channels^[10]

Erythematotelangiectatic rosacea (ETR)

Papulopustular rosacea (PPR)

Phymatous rosacea (PhR)

TRPV1

Increased gene expression

Increased gene expression

TRPV2

Increased dermal immunolabeling

Increased immunoreactivity, increased gene expression

Decreased epidermal staining

TRPV3

Increased dermal immunolabeling

Increased dermal immunostaining, increased gene expression

TRPV4

Increased immunoreactivity

Increased dermal immunostaining

TRP channels activated by temperature:

TRPA1 and TRPV1 channels have shown distinct thermal activation thresholds. Due to the current evidence, a review paper hypothesized that TRPV1 channels are activated by hot temperatures and TRPA1 channels are activated by cold temperatures. This activation of TRP channels then mediates the release of neuropeptides that induce inflammation in rosacea.^[8]

Food and the TRP Channel Connection

TRP Channels’ Effects on Skin

Patients can experience increased skin sensitivity and episodes of burning after eating spices. TRPV-1 can be found in skin cells and endothelial cells of capillaries in the dermis.^[13] Non-neuronal TRPV 1-4 cation channels have been shown to be differentially regulated in patients with rosacea.^[10]

Selective TRPV 1 antagonists seem to inhibit flare responses, pain, and heat hyperalgesia to capsaicin, heat, and UVB light respectively.^[14] These findings suggest that TRPV-1 channels might play a role in the pathogenesis of rosacea since capsaicin and heat are common triggers for rosacea.^[15]

Spices, Heat & Temperature

Exogenous agonists for TRPA1 and TRPV1 channels are associated with the compounds in vegetables and spices. Capsaicin can activate TRPV1 and cinnamaldehyde can activate TRPA1, which all leads to an acute painful burning sensation which may be similar to that observed in rosacea.^[8]

Temperature can also affect rosacea flare-ups by activating the TRP channels that are sensitive to temperature. Specific triggers such as temperature changes can activate the channels which then mediate the symptoms of rosacea such as inflammation and flushing. ^[10]

Both food that contains the compound capsaicin, which is present in spicy foods such as hot chili peppers, can activate TRPV1 channels and food that is considered moderately hot, greater than or equal to 43 degrees Celsius, can also activate TRPV1 channels. This shows that “hot” foods and foods that have high thermal heat activate the same receptors which can contribute to the symptoms in rosacea. ^[16] 

Coffee

A study proposed a connection between coffee intake and provoked flushing in people with erythematotelangiectatic rosacea. The article found no connection between the caffeine and symptoms but rather a connection between heat and symptoms.10 Caffeine nor coffee at temperatures of 22° C produced flushing in patients. At 60° C both coffee and water led to flushing suggesting that the flushing produced from coffee at 60° C is from the heat, not the caffeine.^[17]

List of food compounds that activate TRP channels:

TRPV1 agonists:^[18]

• Capsiate
• Capsiconiate
• Capsainol from hot and sweet peppers
• Several piperine analogs from black pepper
• Gingeriols
• Shogaols from ginger
• Sanshools and hydroxysanshools from sansho (Japanese pepper) 

TRPA1 agonists:^[18]

• Several sulfides from garlic and durian
• Hydroxy fatty acids from royal jelly
• · Miogadial and miogatrial from mioga
• Piperine analogs from black pepper
• ACA from galangal

In summary, evidence shows that certain foods and high temperatures can cause rosacea flares and that these reactions can be mediated through the activation of TRP channels. When these channels are activated, they release neuropeptides that cause inflammation and vasodilation.

Practical Tips

• Advise patients on the role that food can play in flaring their rosacea and which foods to avoid.
• Advise patients wanting to drink coffee that the heat from coffee, not the caffeine content, likely provokes symptoms in patients with rosacea.
• As TRP channels play a role in the pathogenesis of rosacea, drugs designed to target TRP channels might help alleviate rosacea symptoms.