Two forms are described in this category: Allergic Fungal Sinusitis and Sinus Mycetoma/ball.
ALLERGIC FUNGAL SINUSITIS
A combination of type 1 and 3 hypersensitivity reaction is thought to be involved in the pathogenesis of Allergic fungal sinusitis.
It is thought to involve direct stimulation of eosinophils by a subset of helper T cells (TH2) primed by fungal antigens.
It results in vigorous inflammation and polyp formation.
Causative organisms includes usually those of the Dematiaceae family, but Aspergillus species are also seen.
Patients usually presents with features of chronic sinusitis.
The diagnostic criteria for allergic fungal sinusitis (AFS) are the presence of characteristic allergic mucin, type I hypersensitivity (eosinophilic-lymphocytic inflammation), absence of fungal invasion, immuno-compromised individuals and radiological confirmation (areas of high attenuation on CT scan).
Patients are treated with systemic steroids, surgery, and nasal irrigations.
Topical Steroids are indicated post-surgery.
SINUS MYCETOMA/BALL
This condition is usually unilateral and involves the maxillary sinus.
Mucopurulent, cheesy, or claylike material is present at the time of surgery.
Patients with sinusitis mycetoma are immunocompetent.
Allergic conditions and fungus-specific IgE are less common.
INVASIVE FUNGAL SINUSITIS
Invasive fungal sinusitis includes the acute fulminant type, which has a high mortality rate if not recognized early and treated aggressively, and the chronic and granulomatous type
ACUTE INVASIVE FUNGAL SINUSITIS– MUCORMYCOSIS
Caused by – rhizopus, rhizomucor, cunninghamella.
The higher prevalence of mucormycosis in India turned out to be statistically significant in comparison with all other countries
Predisposing factors:
Organ transplant recipients
Long term desferroxamine therapy
Immunosuppression due to steroids or cytotoxic drugs
Hematological malignancy
Diabetis Mellitus
Chronic renal failure
Five forms of mucormycosis are:
Rhinocerebral (most common site)
Pulmonary mucormycosis (2nd most common)
Cutaneous
Gastrointestinal
Disseminated
Miscellaneous
Clinical Presentation
Intitially, the disease runs a subtle course with only fever and rhinorrhea. Later on, it invades the orbit and intracranial cavity with rapid loss of vision, meningitis, cavernous sinus thrombosis and multiple cranial nerve palsies.
It has marked predilection for vascular invasionleading to widespread thrombosis, tissue necrosis, and gangrene.
Characteristic nasal finding is a dark necrotic turbinate surrounded by pale mucosa blackish discharge and crusts.
M/C site is middle turbinate followed by middle meatus and septum.
Investigation of choice is MRI, while biopsy is confirmatory.
Diagnosis: Biopsy with histopathologic examination is the most sensitive and specific modality for definitive diagnosis. Biopsy shows wide, thick walled, ribbon like, aseptate hyphal elements that branch at acute angles.
Histologic examination of affected tissue reveals either infarction, with invasion of blood vessels by many fungal hyphae, or acute necrosis, with limited inflammation and hyphae.
Treatment: Includes IV amphotericin-B, heparin, hyperbaric oxygen, and surgical debridement.
CHRONIC INVASIVE FUNGAL SINUSITIS
It is a slowly progressive fungal infection with a low-grade invasive process and usually occurs in patients with diabetes.
Orbital apex syndrome, which is characterized by a decrease in vision and ocular immobility due to a mass in the superior portion of the orbit, is usually associated with this condition.
Aspergillus fumigatus is the only fungus associated with chronic invasive fungal sinusitis.
On microscopy,shows hyaline, narrow, septate and irregular branching hyphae with invasion of the blood vessels ..
GRANULOMATOUS INVASIVE FUNGAL SINUSITIS
This condition has been reported almost exclusively in immunocompetent individuals from North Africa.
Generally, proptosis is associated with granulomatous invasive fungal sinusitis.
Aspergillus flavus exclusively has been associated with granulomatous invasive fungal sinusitis.
Exam Question
The diagnostic criteria for allergic fungal sinusitis (AFS) are the presence of characteristic allergic mucin, type I hypersensitivity (eosinophilic-lymphocytic inflammation), absence of fungal invasion, immuno-compromised individuals and radiological confirmation (areas of high attenuation on CT scan).
Type 1 and Type 3 Allergic reaction is seen in patients with Allergic fungal sinusitis.
Causative organism in a diabetic with orbital cellulitis and maxillary sinusitis showing hyaline, narrow, septate and irregular branching hyphae with invasion of the blood vessels on microscopy would be Aspergillus.
Mucormycosis has a predilection for vascular invasion.
Orbital mucormycosis may occur as a complication of Diabetic Ketoacidosis.
Amphoterecin B IV is used for invasive fungal sinusitis.
Don’t Forget to Solve all the previous Year Question asked on Fungal Sinusits
REF: Harrison 17th ed p 1261, International Journal of Infectious Diseases Volume 15, Issue 8, Pages e533-e540, August 2011
Mucormycosis
Caused by — rhizopus , rhizomucor , cunninghamella
Moulds with non septate hyphae
The higher prevalence of mucormycosis in India turned out to be statistically significant (p < 0.0001) in comparison with all other countries
Predisposing factors
– Organ transplant recipients
– Long term desferroxamine therapy
– Immunosuppression due to steroids or cytotoxic drugs
– Hematological malignancy
– Diabetics
– Chronic renal failure
Five forms
Rhinocerebral (most common site)
Pulmonary mucormycosis (2nd most common)
Cutaneous
Gastrointestinal
Disseminated
Diagnosis:
Microscopy and biopsy show organisms that appears as broad ribbon like usually non septate hyphae which branch at right angles
Q. 2
Mucormycosis of paranasal sinus is most common in
A
HIV
B
Diabetes
C
Those on immuno suppressants
D
Post surgical
Q. 2
Mucormycosis of paranasal sinus is most common in
A
HIV
B
Diabetes
C
Those on immuno suppressants
D
Post surgical
Ans.
B
Explanation:
MUCORMYCOSIS:
Caused by – rhizopus , rhizomucor , cunninghamella
Moulds with non septate hyphae
The higher prevalence of mucormycosis in India turned out to be statistically significant (p < 0.0001) in comparison with all other countries
Predisposing factors
– Organ transplant recipients
– Long term desferroxamine therapy
– Immunosuppression due to steroids or cytotoxic drugs Hematological malignancy
– Diabetics
– Chronic renal failure
Five forms
Rhinocerebral (most common site)
Pulmonary mucormycosis (2′ most common)
Cutaneous
Gastrointestinal
Disseminated
Diagnosis:
Microscopy and biopsy show organisms that appears as broad ribbon like usually non septate hyphae which branch at right angles
Q. 3 True about Mucormycosis is:
A
Nose is a common site
B
Diabetes mellitus is predisposing
C
Vascular invasion seen
D
All of the above
Q. 3 True about Mucormycosis is:
A
Nose is a common site
B
Diabetes mellitus is predisposing
C
Vascular invasion seen
D
All of the above
Ans.
D
Explanation:
All of the above
Q. 4
Choose the TRUE statement/s about mucormycosis:
A
Nose is a common site
B
Diabetics is a predisposing factor
C
Common in India
D
All of the above
Q. 4
Choose the TRUE statement/s about mucormycosis:
A
Nose is a common site
B
Diabetics is a predisposing factor
C
Common in India
D
All of the above
Ans.
D
Explanation:
Mucormycosis
Caused by – rhizopus, rhizomucor, cunninghamella. The higher prevalence of mucormycosis in India turned out to be statistically significant (p < ? 0001. in comparison with all other countries
Predisposing factors:
Organ transplant recipients
Long term desferroxamine therapy
Immunosuppression due to steroids or cytotoxic drugs
Hematological malignancy
Diabetis Mellitus
Chronic renal failure
Five forms of mucormycosis are:
Rhinocerebral (most common site)
Pulmonary mucormycosis (2nd most common)
Cutaneous
Gastrointestinal
Disseminated
Miscellaneous
Diagnosis: Biopsy with histopathologic examination is the most sensitive and specific modality for definitive diagnosis. Biopsy shows wide, thick walled, ribbon like, aseptate hyphal elements that branch at acute angles.
Q. 5
TRUE about mucormycosis is:
A
Not seen in India
B
Nose is a common site
C
Diabetes is not a predisposing factor
D
Metachromatic bodies are seen
Q. 5
TRUE about mucormycosis is:
A
Not seen in India
B
Nose is a common site
C
Diabetes is not a predisposing factor
D
Metachromatic bodies are seen
Ans.
B
Explanation:
Mucormycosis: is an opportunistic mycosis caused by fungi of class zygomycetes.
Mucor and rhizopus species are the most common agents to cause Zygomycoses.
These fungi are ubiquitious worldwide in soil, manure and decaying organic matter.
Mucoracae are commonly cultured from the nose, throat, mouth and feces of many healthy individuals.
The most common clinical presentation is induration of the skin with surrounding erythema with rapidly progressing to necrosis.
Conditions that predispose:
Acidosis associated with diabetes mellitus
Organ transplant recipients
Long term desferroxamine therapy
Immunosuppression due to steroids or cytoxic drugs
Hematological malignancy leukaemia, lymphoma
Chronic renal failure
Severe burn
Good to know:
Rhinocerebral mucormycosis is a rare opportunistic infection of the sinuses, nasal passages, oral cavity, and brain caused by saprophytic fungi (rhizopus, mucor). Most commonly seen in immunocompromised individual.
Ref: Jawetz, ‘Medical microbiology’, 23rd Edition, Page 650; Textbook of Microbiology,By R. Ananthanarayan, C.K. Jayaram Paniker, 7th Edition, Page 625.
Q. 6
All of the following are diagnostic criteria of Allergic Fungal Sinusitis (AFS), EXCEPT:
A
Areas of High Attenuation on CT scan
B
Orbital invasion
C
Allergic Eosinophilic mucin
D
Type I Hypersensitivity
Q. 6
All of the following are diagnostic criteria of Allergic Fungal Sinusitis (AFS), EXCEPT:
A
Areas of High Attenuation on CT scan
B
Orbital invasion
C
Allergic Eosinophilic mucin
D
Type I Hypersensitivity
Ans.
B
Explanation:
The diagnostic criteria for allergic fungal sinusitis (AFS) are the presence of characteristic allergic mucin, type I hypersensitivity (eosinophilic-lymphocytic inflammation), absence of fungal invasion, immuno-compromised individuals and radiological confirmation (areas of high attenuation on CT scan).
Q. 7
Which type of Allergic reaction is seen in patients with Allergic fungal sinusitis?
A
Type 1 and Type 2
B
Type 2 and Type 3
C
Type 1 and Type 3
D
Type 4 and Type 1
Q. 7
Which type of Allergic reaction is seen in patients with Allergic fungal sinusitis?
A
Type 1 and Type 2
B
Type 2 and Type 3
C
Type 1 and Type 3
D
Type 4 and Type 1
Ans.
C
Explanation:
A combination of type 1 and 3 hypersensitivity reaction is thought to be involved in the pathogenesis of Allergic fungal sinusitis.
It is thought to involve direct stimulation of eosinophils by a subset of helper T cells (TH2) primed by fungal antigens.
It results in vigorous inflammation and polyp formation.
Causative organisms includes usually those of the Dematiaceae family, but Aspergillus species are also seen.
Patients usually presents with features of chronic sinusitis.
Patients are treated with systemic steroids, surgery, and nasal irrigations.
Q. 8
An elderly diabetic has left sided orbital cellulites, CT scan of paranasal sinuses shows evidence of left maxillae sinusitis. Gram stained smear of the orbital exudates shows irregularly branching septate hyphae. The following is the most likely aetiological agent –
A
Aspergillus
B
Rhizopus
C
Mucor
D
Candida
Q. 8
An elderly diabetic has left sided orbital cellulites, CT scan of paranasal sinuses shows evidence of left maxillae sinusitis. Gram stained smear of the orbital exudates shows irregularly branching septate hyphae. The following is the most likely aetiological agent –
A
Aspergillus
B
Rhizopus
C
Mucor
D
Candida
Ans.
A
Explanation:
Ans. is `a’ i.e., Aspergillus
Septate hyphae and involvement of sinuses suggets the diagnosis of Aspergillus infection.
Aspergillus can cause sinusitis and the hyphae of Aspergillus are septate and branched.
Q. 9
Mucormycosis-
A
Angio-invasion
B
Lymph invasion
C
Septate hyphae
D
All
Q. 9
Mucormycosis-
A
Angio-invasion
B
Lymph invasion
C
Septate hyphae
D
All
Ans.
A
Explanation:
Ans. is ‘a’ i.e., Angio-invasion
MUCORMYCOSIS
Mucormycosis is most commonly caused by species ofRhizopus, Rhizomucor and Cunninghamella, but species of Apophysomyces, saksenaea, mucor and Absidia also are occasionally responsible.
They appear as nonseptate hyphae in tissues.
In all forms of mucormycosis, vascular invasion (angio-invasion) is a prominant feature.
. Ischemic or hemorrhagic necrosis is the foremost histological finding.
. Predisposing factors:
a) For paranasal sinus
Diabetes 1. Hematological malignancies
Organ transplantation 2. Long term deferoxamine therapy b)For Gastrointestinal mucormycosis
Uremia 3. Diarrhea] disease
Severe malnutrition
– Primary cutaneous inoculation is uncommon but occurs in burn eschars, underneath occlusive dressings, and sites of minor trauma in immunocompromized adults and low-birth-weight neonates.
Treatment
Debridement plus amphotericin B.
Q. 10
Orbital mucormycosis is a complication of
A
AIDS
B
Steroid therapy
C
Cushing’s disease
D
Diabetic ketoacidosis
Q. 10
Orbital mucormycosis is a complication of
A
AIDS
B
Steroid therapy
C
Cushing’s disease
D
Diabetic ketoacidosis
Ans.
D
Explanation:
Ans. is ‘d’ i.e., Diabetic ketoacidosis
Note – Orbital mucormycosis occurs secondary to paranasal sinus mucormycosis.
Predisposing factors for paranasal sinus mucormycosis
– Diabetes mellitus – Long term deferoxamine therapy
– Hematological malignancies – Organ transplantation
. Predisposing factors for G.I. mucormycosis
– Uremia – Diarrheal diseases
– Severe malnutrition
Q. 11
Which among the following is true regarding fungal sinusitis:
A
Surgery is required for treatment
B
Most common organism is Aspergillus niger
C
Amphoterecin B IV is used for invasive fungal sinusitis
D
a and c
Q. 11
Which among the following is true regarding fungal sinusitis:
A
Surgery is required for treatment
B
Most common organism is Aspergillus niger
C
Amphoterecin B IV is used for invasive fungal sinusitis
D
a and c
Ans.
D
Explanation:
Q. 12
All of the following are diagnostic criteria of allergic Fungal sinusitis (AFS) except:
A
Areas of High attuenuation on CT scan
B
Orbital invasion
C
Allergic eosinophilic mucin
D
Type 1 Hypersensitivity
Q. 12
All of the following are diagnostic criteria of allergic Fungal sinusitis (AFS) except:
A
Areas of High attuenuation on CT scan
B
Orbital invasion
C
Allergic eosinophilic mucin
D
Type 1 Hypersensitivity
Ans.
B
Explanation:
Allergic fungal sinusitis is a noninvasive form of fungal sinusitis as such orbital invasion is not its feature.
Q. 13
All are true about mucormycosis, except:
A
Lymph invasion
B
Angio invasion
C
Long term deferoxanine therepy
D
b and c
Q. 13
All are true about mucormycosis, except:
A
Lymph invasion
B
Angio invasion
C
Long term deferoxanine therepy
D
b and c
Ans.
D
Explanation:
Mucormycosis is caused by Rhizopus species, Rhizomucus and Absidia species.
Intitially, the disease runs a subtle course with only fever and rhinorrhea. Later on, it invades the orbit and intracranial cavity with rapid loss of vision, meningitis, cavernous sinus thrombosis and multiple cranial nerve palsies.
It has marked predilection for vascular invasion leading to widespread thrombosis, tissue necrosis, and gangrene.
Characteristic nasal finding is a dark necrotic turbinate surrounded by pale mucosa blackish discharge and crusts.
M/C site is middle turbinate followed by middle meatus and septum.
Investigation of choice is MRI, while biopsy is confirmatory.
Treatment: Includes amphotericin-B, heparin, hyperbaric oxygen, and debridement.
Q. 14
Topical steroids are not recommended post-surgery for:
A
Allergic fungal sinusitis
B
Chronic rhinosinusitis
C
Antrochoanal polyp
D
Ethmoidal polyps
Q. 14
Topical steroids are not recommended post-surgery for:
A
Allergic fungal sinusitis
B
Chronic rhinosinusitis
C
Antrochoanal polyp
D
Ethmoidal polyps
Ans.
C
Explanation:
Topical steroids are not recommended in post surgery for antrochoanal polyps.
For antrochoanal polyps, cause is infection and not the allergy.
Antrochoanal polyps are single, unilateral and rarely recur.
Topical steroids are rarely recommended.
Q. 15
A diabetic with orbital cellulitis and maxillary sinusitis shows hyaline, narrow, septate and ranching hyphae with invasion of the blood vessels fungus on microscopy. Which is the causative fungus ?
A
Candida
B
Rhizospora
C
Aspergillus
D
Histoplasma
Q. 15
A diabetic with orbital cellulitis and maxillary sinusitis shows hyaline, narrow, septate and ranching hyphae with invasion of the blood vessels fungus on microscopy. Which is the causative fungus ?
A
Candida
B
Rhizospora
C
Aspergillus
D
Histoplasma
Ans.
C
Explanation:
Ans. is ‘c’ i.e., Aspergillus
Diagnosis of Aspergillus infection:
Histologic examination of affected tissue reveals either infarction, with invasion of blood vessels by many fungal hyphae, or acute necrosis, with limited inflammation and hyphae.
Aspergillus hyphae are hyaline, narrow, and septate, with branching at 45°; no yeast forms are present in infected tissue.
Hyphae can be seen in cytology or microscopy preparations, which therefore provide a rapid means of presumptive diagnosis.
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