Like sunlight, emotional stress can also trigger rosacea. People who develop infections of the eyelids must practice frequent eyelid hygiene. Managing pretrigger events such as prolonged exposure to cool environments can directly influence warm-room flushing. Medications
Medications with good evidence include topical ivermectin and azelaic acid creams and brimonidine, and doxycycline and isotretinoin by mouth. Lesser evidence supports topical metronidazole cream and tetracycline by mouth.Metronidazole is thought to act through anti-inflammatory mechanisms, while azelaic acid is thought to decrease cathelicidin production. Oral antibiotics of the tetracycline class such as doxycycline, minocycline, and oxytetracycline are also commonly used and thought to reduce papulopustular lesions through anti-inflammatory actions rather than through their antibacterial capabilities.Using alpha-hydroxy acid peels may help relieve redness caused by irritation, and reduce papules and pustules associated with rosacea. Oral antibiotics may help to relieve symptoms of ocular rosacea. If papules and pustules persist, then sometimes isotretinoin can be prescribed. The flushing and blushing that typically accompany rosacea are typically treated with the topical application of alpha agonists such as brimonidine and less commonly oxymetazoline or xylometazoline.A review found that ivermectin was more effective than alternatives for treatment of papulopustular acne rosacea. An ivermectin cream has been approved by the FDA, as well as in Europe, for the treatment of inflammatory lesions of rosacea. The treatment is based upon the hypothesis that parasitic mites of the genus Demodex play a role in rosacea. In a clinical study, ivermectin reduced lesions by 83% over 4 months, as compared to 74% under a metronidazole standard therapy.
Ecallantide (trade name Kalbitor) is a drug used for the treatment of hereditary angioedema (HAE) and in the prevention of blood loss in cardiothoracic surgery. It is an inhibitor of the protein kallikrein and a 60-amino acid polypeptide which was developed from a Kunitz domain through phage display to mimic antibodies inhibiting kallikrein. Medical uses
Angioedema
On November 27, 2009, ecallantide was approved by the FDA for the treatment of acute attacks of hereditary angioedema for persons over 16 years of age. A single dose requires three separate injections, which are given under the skin.Ecallantide does not appear to be efficacious for the treatment of angioedema due to ACE inhibitors. Adverse effects
The most common adverse effects are headache, nausea, fatigue and diarrhea. Less common, but observed in more than 5% of patients in clinical trials, are respiratory tract infections, fever, vomiting, itching and upper abdominal pain. Up to 4% of patients showed anaphylaxis, which led to a black box warning in the US. Interactions
As of 2011, no interaction studies have been conducted. Mechanism of action
HAE is caused by a mutation of the C1-inhibitor gene. Defective or missing C1-inhibitor permits activation of kallikrein, a protease that is responsible for liberating bradykinin from its precursor kininogen. An excess of bradykinin leads to fluid leakage from blood vessels, causing swelling of tissues typical of HAE. Ecallantide suppresses this pathogenetic mechanism by selectively and reversibly inhibiting the activity of plasma kallikrein. Ecallantides inhibitory constant (Ki) for kallikrein is 25 picoMolar, indicating high affinity.