1. Trachoma

- Major cause of blindness worldwide

- Due to chlamydia trachomatis types A, B, and C

- Cause follicular conjunctivitis and pannus (neovascularization) formation in cornea. 

- Concurrent infection in nasopharynx can cause nasal discharge

- Diagnose with giemsa stain of conjunctival scrapings

- Tx with topical tetracycline or PO azithromycin, as repeated infections can lead to corneal scarring 

2. Neonatal chlamydial conjunctivitis
- Chlamydial conjunctivitis presents later (around 5-14 days after birth) than gonococcal
- Infants infected with chlamydia have a 30-50% chance of developing conjunctivitis and a 5-30% risk of getting pnemonia.
- Presents with chemosis, eyelid swelling, watery/mucopurulent discharge
- Cannot be prevented with topical eye drops
- Mange by testing mom - standard is testing at first prenatal visit for all women, and then repeat testing in 3rd trimester for all "higher risk" women - anyone under 25, women with new or multiple partners, inconsistent condom use.
- These kids can also get chlamydial pneumonia at around 1-3 months.
- Treat both conjunctivitis and pneumonia with 14 day course of PO erythromycin (note: there is a risk of hypertrophic pyloric stenosis with systemic erythromycin but in this case the cost clearly outweighs the benefit)
3. Gonococcal conjunctivitis
- Aka ophthalmia neonatorum
- Presents at 2-5 days after birth
- Eyelid swelling and copious purulent discharge
- Prevent with erythromycin ointment in eyes within 1 hour of birth
4. Paget's disease 
- hearing loss
- elevated alk phos may be the only aberrant lab (Ca, Phos, PTH all normal)
5. Transdermal patches take 8-12 hours to take full effect
6. Severe hypomagnesemia may mimic hypocalcemia as it causes decreased PTH secretion and decreased peripheral responsiveness to PTH
{some guidelines for electrolyte replacement dosing}
7. DDx for renal transplant dysfunction: 
- Calcineurin inhibitor toxicity (most studies have been with cyclosporine/sandimmune but tacrolimus/prograf is believed to have similar toxicity) - mechanism is believed to be vasoconstriction of afferent and efferent arterioles
- Acute rejection (tx with IV steroids)
- Ureteral obstruction
- Vascular obstruction
- ATN
8. HGSIL on pap smear in pregnant women: 
- Nearly 50% of HGSIL (pap) and CIN 2/3 (bx) will regress spontaneously during pregnancy; progression to invasive carcinoma is rare (<0.5%)
- If HGSIL is found, pt should get coloposcopy to exclude invasive cervical cancer. Neg colpo- repeat pap and colpo 6 weeks after delivery. Abnormal colpo - biopsy suspicious lesions. If CIN 2 or 3, then repeat cytology biopsy at 12+ week intervals
- Invasive procedures on the cervix (i.e. biopsy, LEEP) should be avoided on pregnant women unless there is a lesion present that suggests invasive cancer
9. Brain death
- Vagal control of the heart is lost - heart rate becomes invariant, and does not respond to atropine.
- Apnea test - no spontaneous respiration at PCO2 of 50+
- No reactive pupils, no oculovestibular reaction
10. Vectors 
- Rabies - Generally reservoirs are carnivores and bats - Raccoons are most prevalent rabid animal in US, esp east coast (caues Hydrophobia and aerophobia - the feeling of water or air triggers involuntary pharyngeal muscle spasms)
- West nile - mosquitos - culex species in the US
- Malaria - mosquitos - anopheles
- Dengue - mosquitos - aedes aegypti - bites during the DAY so if question stem says "patient was sleeping under mosquito net" they can still have dengue! This one way you distinguish from malaria.
- Lyme - tick - ixodes (deer) tick
- RMSF - tick - dermacentor (dog) tick