Updated: Sep 15
What is invasive fungal sinusitis? How to differentiate it from other types of fungal sinus infections?
Fungal sinus infections are three types, or we can term these stages also, and their occurrence depends more on the person’s immunity and not on the kind of the fungus.
Non-invasive fungal sinusitis
Invasive fungal sinusitis a. Granulomatous invasive fungal sinusitis b. Non-granulomatous invasive fungal sinusitis
Fulminant fungal sinusitis
Most fungal sinusitis cases are non-invasive, and they limit to the nasal cavity (in the nose) and sinuses. However, if immunity gets compromised, a non-invasive infection can transform into an invasive disease. The fungus that infects the skin lining of the nose and sinuses will move into the deeper tissues, thus making it more dangerous. This type of infection that spreads into the tissues is invasive fungal sinusitis. In some we see a rare symptom where the disease is untreated or incorrectly treated, the infection can also spread from tissues to facial skin. So, in non-invasive fungal sinusitis, the fungus only lives on the sinus cavity. But, in invasive fungal infection, the fungus lives in tissues. Sometimes the patient could be having both invasive and non-invasive infections at different places. For example, the patient could have a non-invasive fungal infection in the nose or maxillary sinus and invasive fungal infection in other sinuses like sphenoid sinus. The ENT doctor must carefully check for both.
Difference between Granulomatous and Non-granulomatous invasive fungal sinusitis
Granulomas are well-developed immune system cells present around the fungus and try to fight the fungal infection. If these granulomas are present around the fungal infection, it will be granulomatous fungal sinusitis. Else, it is called non-granulomatous fungal sinusitis. Given the right combination of medicines, recovery is quicker for a granulomatous fungal sinus infection than for a non-granulomatous fungal sinus infection.
How is invasive fungal sinusitis different from fulminant fungal sinusitis?
Mucormycosis and Aspergillosis fungal sinusitis, commonly known as black and white fungus respectively, are invasive fungal sinusitis but come under a subtype called fulminant. Although fulminant comes under invasive, when we say invasive fungal sinusitis we always refer to non-fulminant invasive fungal sinusitis. Immunity is more compromised in fulminant than an invasive fungal infection. In these fulminant infections, the spread is faster, and the infection can double up in hours. Whereas Invasive fungal sinusitis far more time to double up. This characteristic makes them so distinctive that a doctor can easily differentiate these two types of diseases based on the timeline of the symptoms, although both infections have similar symptoms. The differentiating feature of fulminant infection is that the disease spreads to the blood vessels.
The mortality rate is higher in the fulminant fungal infection as it can spread faster than invasive fungal sinusitis as fulminant can reach the brain within a few weeks if not treated. Thankfully it will take years for the invasive fungal sinusitis to do the same, giving us time to deal with it. When treated early, the mortality rate of fulminant fungal sinusitis is 30%, but if treated, the mortality rate is almost zero for invasive fungal sinusitis.
The type of fungal infection depends solely on immunity. Low immunity means non-invasive type, very low means invasive type, very very low means fulminant type.
Invasive fungal sinusitis symptoms
The infection can spread from sinuses to other parts nearby sinuses, hence here are the invasive fungal sinusitis symptoms.
Pain and/or swelling in the eye, nose, teeth, or cheek
Vision disturbances – double vision or diminishing vision
Loosening of the teeth when the infection spreads to the jaw bone
Loss of sensation of cheek
Swelling of the face if it spreads to the skin – a rare condition
When it spreads to the brain, the body part controlled by that part of a particular brain area will be affected.
Example: In one of the invasive fungal sinusitis cases seen by Dr. K. R. Meghanadh, the left side of the brain that controls the right arm got invaded by the disease. The infection resulted in paralysis of the right arm.
Invasive fungal sinusitis symptoms and fulminant sinusitis symptoms are the same. Still, an ENT doctor can easily distinguish the symptoms as they progress slowly in invasive compared to fulminant infection in invasive fungal sinusitis.
Diagnosis of invasive fungal sinusitis
Diagnosis of invasive fungal sinusitis involves Histopathology of biopsy. Biopsy means the removal of a small piece of tissue from the body. Histopathology is cutting the tissue specimen into thin slices, staining the structures of the cells in the thin slices, and examining them under a microscope. Each disease will exhibit specific signature features under the microscope. An expert pathologist may do other stains defining the characteristics of the various cells and their pattern to confirm the diagnosis. However, the ENT doctor's main task is to find which part of the body is the best representative of the disease to do a biopsy. To understand which is the best representative of the disease, an ENT doctor must perform a few tests initially. The initial tests are nasal endoscopy, MRI, and CT scan. The experience of an ENT surgeon will come in handy in determining the part of the body, i.e., the best representative of the disease. As discussed before, various types of fungal infections can coexist in the body, and an ENT surgeon can identify these correctly.
The ENT surgeon should give the picture of behavior, symptoms, and nasal endoscopy to the pathologist and help him make an accurate diagnosis. As per the ENT surgeon’s suggestion, the pathologist will look for special fungal stains, as the fungus is not visible in ordinary stains. The pathologist will determine if the infection is in the tissue or surface. If the infection is in the tissue, it is an invasive infection. If it is invasive, the pathologist will look for granuloma formation. In fulminant fungal sinusitis, the fungal mycelia are also visible within the blood vessels.
Invasive fungal sinusitis treatment
Many doctors suggest extensive surgeries for invasive fungal sinusitis treatment. The treatment suggested involves removing parts or disturbing the function of the nose, sinuses, and face. Dr. K. R. Meghanadh opposes these extensive surgeries in the case of invasive fungal sinusitis. His experience taught him that the treatment should rely on antifungal drugs rather than removing the parts of the body which will result in loss of function and cosmetic deformity. The recovery time will depend on the fungal load. Although the recovery is slow, the function of the body is maintained with the least deformity. On the contrary, extensive removal of the invasive fungal disease may result in loss of certain functions like the smell and gross disfigurement of the face.
However, surgical removal along with antifungal medical treatment is essential in fulminant fungal infections, and the surgery often has multiple sittings. In fulminant fungal sinusitis loss of functions and disfigurement is traded to save the life, as the disease progression is very fast and medicines alone cannot kill the fungus completely. The point to be remembered is in fulminant infections where the fungal load is very high and cannot be tackled by antifungal medication, hence the load is reduced by surgical debridement to the extent it can be managed by antifungals. Whereas, in invasive fungal sinusitis the load is not that high and progression is exponentially slow compared to the fulminant.
Rare cases of infection spreading to the skin
As mentioned earlier, in very rare cases, when either the infection is ignored or misdiagnosed, or treated wrongly, the infection can spread from tissues to the facial skin.
Rare extreme example case report by author
A young lady has started developing a swelling on the left cheek at the age of 23 years, which has gradually progressed with disturbance in vision, nose block, headache, and disfigurement of the face. She consulted and took various treatments from allopathy and alternative medicines for two years. She finally planned for surgery by a plastic surgeon.
At this stage, when she was 25, she consulted the author in 2017 and it was suspected as invasive fungal granuloma. After the investigations with the help of an endoscope, a simple biopsy was performed without a scar on the face. The diagnosis was confirmed, and treatment was started with intravenous antifungals for 32days and later followed with oral medications. The blood parameters were checked at regular intervals.
Currently, facial appearance has improved phenomenally. All the complaints have subsided. Her condition will improve and her face and skin will be normal in two years.
The takeaway from this case
This case study reiterates that disfigurement and loss of function can be avoided and treated with antifungal medication only in invasive fungal sinusitis. Extensive surgery must be avoided, even if the infection is high. In the above case, the only procedure done on the patient was a biopsy which can be considered minor surgery, which was done to get proper diagnosis only and not for the treatment of the disease.
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