eMedicine Specialties > Ophthalmology > Infectious Disease

Trachoma: Differential Diagnoses & Workup

Author: Anthony W Solomon, MBBS, DTM&H, PhD, MRCP, Specialist Registrar in Infectious Diseases, Lister Unit, Northwick Park Hospital, London; Honorary Lecturer, International Centre for Eye Health, Clinical Research Unit, London School of Hygiene and Tropical Medicine, London
Coauthor(s): Hugh Ringland Taylor AC, MD, MBBS, BmedSc (Melb), DO (Melb), FRACO, FRACS, FAAO, FACS, FAICD, Harold Mitchell Professor of Indigenous Eye Health, School of Population Health, University of Melbourne
Contributor Information and Disclosures

Updated: Sep 5, 2007

Differential Diagnoses

Conjunctivitis, Allergic
Conjunctivitis, Bacterial
Conjunctivitis, Neonatal
Conjunctivitis, Viral
Trichiasis

Other Problems to Be Considered

Acute chlamydial infection (inclusion conjunctivitis)
Toxic follicular conjunctivitis (secondary to topical medications or other compounds)

Workup

Laboratory Studies

  • In endemic areas, the diagnosis is almost always based on the clinical appearance.
  • Laboratory assays are principally used in research.
    • To confirm that the clinical diagnosis of active trachoma is the result of ocular C trachomatis infection, the best laboratory techniques are the nucleic acid amplification tests (NAATs), of which the polymerase chain reaction (PCR) is one example.
    • The NAATs have high sensitivity and specificity but are too expensive and too technically complex to be widely available in most settings where trachoma is endemic.
    • On any assay, apparent false-positive and false-negative results (compared with the clinical signs of active trachoma) may be related to the natural history of infection and disease.
    • Individuals become infected several weeks before specific clinical signs appear, and evidence of conjunctival inflammation persists for weeks to months after the infection resolves.
    • Other useful techniques are direct fluorescein-labeled monoclonal antibody (direct fluorescent antibody [DFA]) assay and enzyme immunoassay (EIA) of conjunctival smears. These tests are less sensitive than the NAATs.  However, to determine whether antibiotics are needed by a community, the prevalence of infection may be an important parameter, so a test with high specificity may be useful even if it has lower sensitivity.  A dipstick-based EIA for infection that can be deployed in remote trachoma-endemic villages has now been developed and has shown good performance characteristics in early trials.
    • Newer diagnostic methods have superseded cell culture, which was the criterion standard for laboratory diagnosis. Cell culture requires a highly specialized laboratory and is expensive and technically demanding. Cell culture has virtually 100% specificity but only moderate sensitivity.
    • Giemsa cytology is microscopic examination of stained conjunctival scrapings for intracytoplasmic inclusions. Giemsa cytology is technically demanding. This test has high specificity but low sensitivity.

More on Trachoma

Overview: Trachoma
Differential Diagnoses & Workup: Trachoma
Treatment & Medication: Trachoma
Follow-up: Trachoma
Multimedia: Trachoma
References
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References

  1. Bobo LD, Novak N, Munoz B, Hsieh YH, Quinn TC, West S. Severe disease in children with trachoma is associated with persistent Chlamydia trachomatis infection. J Infect Dis. Dec 1997;176(6):1524-30. [Medline].

  2. Dawson CR, Schachter J, Sallam S, Sheta A, Rubinstein RA, Washton H. A comparison of oral azithromycin with topical oxytetracycline/polymyxin for the treatment of trachoma in children. Clin Infect Dis. Mar 1997;24(3):363-8. [Medline].

  3. Grayston JT, Wang SP, Yeh LJ, Kuo CC. Importance of reinfection in the pathogenesis of trachoma. Rev Infect Dis. Nov-Dec 1985;7(6):717-25. [Medline].

  4. Mabey DC, Solomon AW, Foster A. Trachoma. Lancet. Jul 19 2003;362(9379):223-9. [Medline].

  5. Reacher M, Foster A, Huber J. Trichiasis surgery for trachoma: the bilamellar tarsal rotation procedure. WHO/PBL 93.29. Geneva: World Health Organization;. 1993.

  6. Solomon A, Burton M. What's new in azithromyin?. Community Eye Health. Dec 2004;17(52):54-6. [Medline].

  7. Taylor HR, Johnson SL, Schachter J, Caldwell HD, Prendergast RA. Pathogenesis of trachoma: the stimulus for inflammation. J Immunol. May 1 1987;138(9):3023-7. [Medline].

  8. Thylefors B, Dawson CR, Jones BR, West SK, Taylor HR. A simple system for the assessment of trachoma and its complications. Bull World Health Organ. 1987;65(4):477-83. [Medline].

  9. West S, Munoz B, Lynch M, Kayongoya A, Chilangwa Z, Mmbaga BB, et al. Impact of face-washing on trachoma in Kongwa, Tanzania. Lancet. Jan 21 1995;345(8943):155-8. [Medline].

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Further Reading

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Keywords

Chlamydia trachomatis, C trachomatis, chronic keratoconjunctivitis, SAFE strategy for trachoma, trichiasis, simplified trachoma grading scheme, trachomatous scarring, corneal opacity

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Contributor Information and Disclosures

Author

Anthony W Solomon, MBBS, DTM&H, PhD, MRCP, Specialist Registrar in Infectious Diseases, Lister Unit, Northwick Park Hospital, London; Honorary Lecturer, International Centre for Eye Health, Clinical Research Unit, London School of Hygiene and Tropical Medicine, London
Anthony W Solomon, MBBS, DTM&H, PhD, MRCP is a member of the following medical societies: Royal College of Physicians of the United Kingdom
Disclosure: Pfizer Inc Grant/research funds Researcher; International Trachoma Initiative Grant/research funds Researcher; Pfizer Inc Support to attend the Trachoma Scientific Exchange in Phoenix, 2006 Review panel membership

Coauthor(s)

Hugh Ringland Taylor AC, MD, MBBS, BmedSc (Melb), DO (Melb), FRACO, FRACS, FAAO, FACS, FAICD, Harold Mitchell Professor of Indigenous Eye Health, School of Population Health, University of Melbourne
Hugh Ringland Taylor AC, MD, MBBS, BmedSc (Melb), DO (Melb), FRACO, FRACS, FAAO, FACS, FAICD is a member of the following medical societies: American Academy of Ophthalmology, American Ophthalmological Society, and Association for Research in Vision and Ophthalmology
Disclosure: Nothing to disclose.

Medical Editor

Anastasios J Kanellopoulos, MD, Assistant Program Director, Clinical Associate Professor, Department of Ophthalmology, Manhattan Eye, Ear, and Throat Hospital, New York University
Anastasios J Kanellopoulos, MD is a member of the following medical societies: American Academy of Ophthalmology, Association for Research in Vision and Ophthalmology, Eye Bank Association of America, and International Society of Refractive Surgery
Disclosure: Nothing to disclose.

Pharmacy Editor

Simon K Law, MD, PharmD, Assistant Professor of Ophthalmology, Jules Stein Eye Institute; Chief of Section of Ophthalmology Surgical Services, Department of Veterans Affairs Healthcare Center, West Los Angeles
Simon K Law, MD, PharmD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, and Association for Research in Vision and Ophthalmology
Disclosure: Nothing to disclose.

Managing Editor

Christopher J Rapuano, MD, Professor, Department of Ophthalmology, Jefferson Medical College; Co-Chairman of the Cornea Service, Co-Chairman of Refractive Surgery Department, Wills Eye Hospital
Christopher J Rapuano, MD is a member of the following medical societies: American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery, Eye Bank Association of America, Pennsylvania Medical Society, and Philadelphia County Medical Society
Disclosure: Allergan Honoraria Speaking and teaching; Allergan Consulting fee Consulting; Alcon Honoraria Speaking and teaching; Inspire Honoraria Speaking and teaching; RPS Ownership interest Other

CME Editor

Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri
Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Hampton Roy Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, and Pan-American Association of Ophthalmology
Disclosure: Nothing to disclose.

 
 
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