Tag: Fungal Sinusits

All of the above

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

1. Rhinocerebral (most common site)
2. Pulmonary mucormycosis (2nd most common)
3. Cutaneous
4. Gastrointestinal
5. Disseminated

Diagnosis:

Microscopy and biopsy show organisms that appears as broad ribbon like usually non septate hyphae which branch at right angles

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

1. Rhinocerebral (most common site)
2. Pulmonary mucormycosis (2′ most common)
3. Cutaneous
4. Gastrointestinal
5. Disseminated

Diagnosis:

Microscopy and biopsy show organisms that appears as broad ribbon like usually non septate hyphae which branch at right angles

All of the above

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

• Rhinocerebral (most common site)
• Pulmonary mucormycosis (2nd most common)
• Cutaneous
• Gastrointestinal
• Disseminated
• Miscellaneous

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’, 23^rd Edition, Page 650; Textbook of Microbiology,By R. Ananthanarayan, C.K. Jayaram Paniker, 7^th Edition, Page 625.

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).

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.

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

1. Diabetes                                                1. Hematological malignancies
2. Organ transplantation                          2. Long term deferoxamine therapy b)For Gastrointestinal mucormycosis
3. Uremia                                                   3. Diarrhea] disease
4. 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.

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

Allergic fungal sinusitis is a noninvasive form of fungal sinusitis as such orbital invasion is not its feature.

• 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.

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.

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.