This is most likely either an allergic reaction to something or a respiratory infection such as
Mycoplasma Gallisepticum (MG) or
Infectious Coryza. Does she have any other symptoms? Is there any trauma to the area (like an injury, scab, etc)?
Infectious Coryza is thankfully caused by a bacteria, more specifically, the
Avibacterium Paragallinarum. Since Infectious Coryza is caused by a bacteria, it can be treated by using antibiotics. Another interesting fact about Infectious Coryza is that if a bird is infected with this bacterial infection, they'll most likely get oozing thick yellow snot, pus filled sinuses or even one or both eyes and an awful fishy-like odor that comes from their nares, mouth or eyes. If there is no smell, then it's most likely not Infectious Coryza that you are dealing with. Once recovered, all birds that have had symptoms and those who were exposed, will be lifetime chronic carriers of this bacteria, shedding and spreading the bacteria from their feces, respiratory secretions and other bodily fluids. During times of stress, symptoms may resurface at any point.
Here are some links to helpful sources about Infectious Coryza:
Mycoplasma Gallisepticum (MG) or
(also known as Chronic Respiratory Disease), is also caused by a bacteria, more specifically, the
Mycoplasmosis (Mycobacterium) bacterium. MG is the MOST COMMON respiratory disease of poultry worldwide, affecting a wide range of poultry fowl and game birds also. This infection can affect the upper respiratory tract and the lower respiratory tract, causing a wide range of different symptoms. MG is most known for the bubbling/foaming or the watering of the eyes, clear-to-cloudy mucus, sneezing, tracheal rales, congestion of the chest, coughing and much, much more. Once recovered, all birds that have had symptoms and those who were exposed, will be lifetime chronic carriers of this bacteria, shedding and spreading the bacteria from their feces, respiratory secretions and other bodily fluids. During times of stress, symptoms may resurface at any point. It is highly recommended not to bring from MG infected flocks because this bacteria is blood-borne and is passed from the mother hen to the hatching chicks, making any that'll hatch, already infected.
Here are some link to helpful sources about MG:
I hope that this can help you and if you have ANY questions, feel free to comment on your post or private message me
. I hope your birds get well as soon as possible, good luck!
