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Snapshot
  • An 8-year-old boy presents to the pediatric emergency department for eye pain and redness. He recently emigrated from Ethiopia to the United States. His parents report that other children in their area also experienced similar symptoms. Physical examination is notable for multiple dome-shaped, yellow-white follicles in the tarsal conjunctiva. He is prescribed oral azithromycin. 
Introduction
  • Overview
    • ocular infection caused by Chlamydia trachomatis
      • serotypes A, B, and C
  • Epidemiology
    • prevalence
      • highest in young children
    • risk factors
      • poor access to water
      • overcrowding
      • poor hygeine
    • transmission
      • ocular and nasal secretions on the fingers
      • fomites
      • eye-seeking flies
        • serves as passive vectors
  • Pathophysiology
    • conjunctival epithelium of the eye leads to an immune response 
      • repeated infections lead to tissue destruction and scarring
  • Prognosis
    • in endemic areas, repeated infections are common
    • corneal opacification may occur in untreated cases
Presentation
  • Symptoms/physical exam
    • follicular conjunctivitis (active disease) 
      • dome-shaped, yellow-white elevations of lymphoid cell collections
      • blood vessels are found around the base
      • Herbert pits 
        • there may be depressions in the upper margin of the cornea
          • this is pathognomonic for trachoma
    • cicatricial disease
      • recurrent infection leads to conjunctival inflammation, which leads to eyelid scarring
        • scarring of the eyelid can distort the lid margin, leading to entropion and trichiasis
Studies
  •  This is a clinical diagnosis
Differential
  • Viral conjunctivitis
    • differentiating factors
      • sandy, burning, or gritty sensation in the eye
      • watery or mucoserous discharge
  • Bacterial conjunctivitis
    • differentiating factors
      • purulent discharge
Treatment
  • Medical
    • oral azythromycin
      • indication
        • treatment of choice
      • comments
        • given that trachoma is a highly contagious, it is effectively transmitted in places with poor hygiene
        • the most effective way of treating this condition is via antibiotic therapy of a mass region
    • topical tetracycline 
      • indication
        • alternative treatment when azithromycin is not available
  • Surgical
    • bilamellar tarsal rotation (BLTR) or posterior lamellar tarsal rotation (PLTR)
      • indication
        • treatment for trichiasis
Complications
  • Corneal abrasions
  • Blindness
 

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Questions (2)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

(M2.OP.12) A 6-year-old immigrant from West Africa is being evaluated after recently arriving to the United States. He is observed to be rubbing and scratching at his eye. On physical exam, the eyelid is everted and the finding is shown in Figure A. This condition is most likely to cause blindness through which mechanism? Review Topic

QID: 105378
FIGURES:
1

Viral infection of the cornea

5%

(1/22)

2

Bacterial infection of the cornea

23%

(5/22)

3

Fungal infection of the cornea

9%

(2/22)

4

Benign growth from conjunctiva onto the cornea

9%

(2/22)

5

Neovascularization of the cornea

50%

(11/22)

M2

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

(M2.OP.5378) A 4-year-old boy who was recently adopted from Ghana is brought to his pediatrician's office. His mother notes he often scratches his right eye and also seems to have poor vision in that eye. On exam, the right eyelid appears similar to Figure A with eversion. Which of the following is the best treatment for this patient? Review Topic

QID: 106991
FIGURES:
1

Topical tetracycline

57%

(13/23)

2

Topical vidarabine

22%

(5/23)

3

Topical prednisone

13%

(3/23)

4

Oral antihistamines

0%

(0/23)

5

Surgical removal of eyelid lesions

4%

(1/23)

M2

Select Answer to see Preferred Response

PREFERRED RESPONSE 1
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