Teaching Evidence Based Medicine: Should We Be Teaching Information Ma...

Keratoacanthoma

ID: 68y/o ♂ came in due to a raised skin lesion on his Lt hand; 

HPI: pt noticed a small area of redness on the dorsal aspect of his Lt hand a few weeks ago; no other skin lesions; no Hx of similar lesions in the past; ROS noncontributory; 

SH: retired, used to work in the logging industry; non smoker; drinks ETOH socially; 

E/O: Looks well; VSSA;

A 1x1cm round nodule on the dorsal surface of the Lt hand; the lesion had a keratin filled central crater; mildly tender to touch; atrophic surrounding skin with mild erythema; no other skin lesions; 

A/P: Pros and cons of excisional Bx were discussed; pt was agreeable and was booked for the procedure; 

Discussion: 

Main DDx if SCC; Bx for definitive Dx and to differentiate from SCC; 

M>F; usually after the age of 50, but can occur at any age; rare below the age of 20; 

Has three stages of development as below,

1. proliferation: may last for 6-8wK; rapid growth to 1-2cm nodule; 
2. maturation: may last for several weeks to several mo; 
3. involution: may last for 4-6wk

First line of treatment is excisional Bx with a 4mm safe margin; Bx should extend to the subcutaneous fat;

KA usually goes through these 3 stages in 4-9mo; 

Referenced: 

1. http://www.uptodate.com/contents/keratoacanthoma-epidemiology-risk-factors-and-diagnosis?source=search_result&search=keratoacanthoma&selectedTitle=2%7E35
2. http://www.uptodate.com/contents/keratoacanthoma-management-and-prognosis?source=see_link
3. http://medicalpicturesinfo.com/wp-content/uploads/2011/09/Keratoacanthoma-2.jpg

Tick bite

ID: 36y/o ♀ otherwise healthy with a suspected tick bite in the ER; 

HPI: was camping in the woods; noticed a mildly painful, small, round, red skin lesion on her thigh; did not see the tick, but is concerned; wants to know if she needs any tests for lyme disease; no fever/chills; ROS non contributory; 

E/O: Looks well; not ill/toxic; VSSA;

A round, well circumscribed, indurated red papule on the Rt medial thigh; mildly tender to touch; no surrounding erythema or bull’s eye appearance; 

A/P: suspected tick bite; daxycyclin 200mg po once; f/u precautions; testing for lyme disease is not recommended; 

Discussion^(1,2): 

Factors affecting disease transmission: 

1. Tick species and stage of development: nymphal stage of deer tick (Ixodes scapulars); 
2. Season: late spring, early summer; 
3. Engorgement: transmission needs >36hr of feeding; tick on the skin needs 24hr before it starts feeding; 

How to remove a tick from skin: 

Grasp the tick with a fine forceps as close to skin as possible; pull straight up; if mouth pieces (does not increase transmission) remain do not try removal (to prevent trauma to skin); do not use other methods such as burning or using chemicals (may irritate the tick ➜ act as a syringe ➜ injects the organism into the host ➜ increases the risk of transmission)

Erythema migrans (EM)⁽³⁾: Characteristic lyme disease rash; bull’s eye appearance; 

Approach to prophylaxis as per Infectious Diseases Society of America (IDSA) guidelines: antibiotic prophylaxis is indicated if the patient meets all the following criteria,

1. Adult or nymphal Ixodes scapularis tick (deer tick).
2. attached for ≥36 hr;
3. Prophylaxis given within the first 72 hours of tick removal.
4. Local rate of infection of ticks with B. burgdorferi is ≥20 percent;
5. No contraindications for Doxycycline (<8 y/o, pregnant, or lactating).

If the patient meets all of these criteria, give doxycycline 200 mg po once (4 mg/kg po once in children >8y/o max dose 200mg). If any contraindications, then no prophylaxis is recommended; 

IgM to B. burgdorferi appears 1-2wk after the signs and sx of lyme disease; IgG appears 2-6wk after the onset of EM; 

  

References: 

1. http://www.cdc.gov/lyme/transmission/blacklegged.html
2. http://www.uptodate.com/contents/evaluation-of-a-tick-bite-for-possible-lyme-disease?source=search_result&search=tick+bite&selectedTitle=1%7E86
3. http://www.bada-uk.org/wp-content/uploads/Erythema_migrans1.jpg

Sudden pop in the Lt ankle while playing soccer

15y/o healthy ♂; was playing soccer; while running backwards, felt a sudden pop a/w immediate onset of severe pain in the left ankle; fell on the ground; wasn’t able to mobilize initially; limping now; no prior similar episodes; no ankle pain prior to this incident; no previous injuries to the Lt ankle; ROS non-contributory; 

PMH: non-contributory; 

E/O: VSSA; 

Lt ankle: mild posterior swelling and ecchymosis; no erythema; no atrophy; tenderness over Achilles tendon with a palpable gap 4cm above its calcaneal insertion; Thompson’s test +ve; 

I/P: Achilles tendon rupture; NSAIDs; RICE; urgent ortho consult; 

Discussion^(1-2):

>75% occur in 30-40 yr olds; Male/Female=10/1; usually happens 30-40min after the start of the activity; Patients feel as if “I was kicked in the back of the leg” a/w a painful snap; 

Total rupture: Thompson’s/Simmonds’ calf squeeze test +ve; “Hatchet strike” defect (palpable, tender defect 3-6cm proximal to the calcaneal insertion) may be present in the immediate post rupture period; not palpable after a few days due to swelling; Only 25% of the tendon fibers are needed for normal Achilles tendon function, hence the difficulty in Dx of partial tears; Weak or absent active dorsiflexion; 

NSAIDs prn; RICE; ortho consult; surgical vs conservative management; needs careful patient selection; recent trend toward conservative Rx with early ROM (cast for 2wk then functional brace); conservative Rx earlier return to function; surgery less re-rupture at 1-4% (conservative at 10-30%), but ↑complications (infection, DVT & PE, adhesions); 

References: 

1. https://itunes.apple.com/ca/app/5-minute-sports-medicine-consult/id445352494?mt=8

2. Brukner, P., Brukner, P., D.R.C.O.G, & Khan, K. (2009). Clinical sports medicine. North Ryde, N.S.W: McGraw-Hill.

Exposure to measles in a 9mo infant

ID: 9 mo/o infant was brought in after exposure to measles; 

HPI: Pt came into contact with an adult family member with skin rash and cold like Sx 5/7 ago; the adult patient was later diagnosed as measles; anxious parents want to know what options if any are available to prevent measles in their child; currently the child is completely asymptomatic;

PMH: non-contributory

E/O: Looks well; VSSA; 

Physical examination is completely normal.

A/P: 

A healthy 9mo/o infant exposed to measles before receiving first MMR injection which was due to be done @ 12mo;

Immune globulin (IG) 0.5ml/kg IM (IGIM) once; continue with the vaccination as planned @ 12-15mo; 

Discussion⁽¹⁾:

General rule (post exposure, non-immune): MMR vaccine within 72h; immune globulin (IG) if >72h but <6d; if non-immune and receive IG should still receive MMR, but not earlier than 6mo after IGIM, and 8mo after IGIV; IG should not be used for outbreak control; 

Post exposure, non-immune, @ ↑risk of complications (infants, pregnant women, immunocompromised) 

Infants ≤12mo: IGIM 0.5ml/kg once (infants 6-11mo may receive MMR, but IGIM preferable to MMR if household contact due to ↑transmission risk); should receive MMR as scheduled @12 mo with second booster prior to school entry; 

Pregnant women: IGIV 400mg/kg once;  

Immunocompromised: IGIV 400mg/kg once; 

Reference: 

1. http://www.uptodate.com/contents/prevention-and-treatment-of-measles?source=search_result&search=measles+prevention&selectedTitle=1%7E150

Ankle pain in a teenager

ID: 13 y/o healthy ♂ with gradual onset of Rt ankle pain 2/52 ago; now limping; not able to fully weight bear on the Rt foot; 

HPI: dull aching pain with activity; no pain at rest; no radiation; pain has gotten worse over the past 2 wk; no recent injury; Hx of mild remote injury 2mo ago while ice skating, did not seek medical advice at that time and the pain resolved completely after a few days, with no pain in the interim; no similar Sx in other joints; no previous similar episodes; involved in competitive ice skating; skipped a few ice skating practice sessions; ⊘fever/chills; ⊘B-Sx; ⊘blurred vision; ⊘GI Sx; ⊘am stiffness; 

PMH: non contributory

E/O: looks well, NAD, VSSA

Rt lower limb: 
Hip and knee joints unremarkable with full ROM.
Ankle: ⊘swelling, ⊘erythema, ⊘skin ▵s, ⊘atrophy, symmetrical compared to the Lt ankle; limited, painful dorsiflexion, ROM otherwise Ⓝ; post. heel area tender to touch; no plantar tenderness; unable to stand on tiptoe due to sever pain; pes planus; neuromuscular unremarkable;  

I/P: Rt heel pain due to Sever’s disease; RICE; reduction of athletic activities; NSAIDs prn; gradual increase of activity when pain better to a pain tolerance level; good quality shoes; vesicoelastic heel caps; f/u if pain refractory to conservative management; 

Discussion(1): 

Sever’s disease (calcaneal apophysitis) is the foot equivalent of Osgood-Schlatter disease; a traction over use syndrome; not an inflammatory condition (apophysitis is a misnomer); pain can be so sever that pt needs to use crutches; 

A cause of late childhood, early adolescent heel pain; most often between the ages of 8 and 13 yr; bilateral in ≈60%; 

Usually pt is involved in sports that need a lot of running (esp. on hard surfaces with low heeled shoes) & jumping; 

Dx is clinical; X-ray is not necessary; medial/lateral compression causes pain in the pos 3rd of the heel; sever pain with standing of tiptoe (Sever sign); Pain on foot dorsiflexion; X-ray if Dx is in question or refractory to conservative Rx (may indicate calcaneal stress # which needs immobilization 3-4wk); 

DDx may include: 

1. calcaneal bursitis
2. Achilles tendinitis
3. plantar fasciitis
4. calcaneal stress #

Rx is conservative if no response ➜ short leg cast or walker boot (duration? probably determined by the severity of the Sx); good quality shoes with adequate shock absorption and firm heel counter; ⊘ long-term sequelae; time to resolution variable, but complete resolution with skeletal maturity; 

Reference: 

1. https://itunes.apple.com/ca/app/5-minute-sports-medicine-consult/id445352494?mt=8

Refractory Hypotension

ID: 51 y/o ♀; new immigrant; found unconscious in her apartment by her daughter, and was brought in by EMS.

HPI: Daughter went to visit her; found her on the floor, non-responsive, but breathing; called 911; no suicide note; no empty pill containers around; as per daughter long-standing depression, worse after immigration; regained consciousness in the ER, and denied suicidal attempt or intentional overdose; ⊘ trauma; ⊘ hemoptysis; ⊘ hematuria; ⊘ hematemesis; ⊘ melena/hematochezia; 

⊘ incontinence. 

PMH: Depression, HTN, DM-II; no prior suicide attempts;

Meds: Atenolol; nifedipine; metformin; atorvastatin; citalopram; ⊘ anticoagulants/antiplatelets; 

All: NKDA 

SH: New immigrant; language barrier; lives alone; ⊘ drugs; ⊘ ETOH;

E/O: responsive to voice; NAD; ⊘ ill/toxic; ⊘ obvious bleeding;

BP: 56/p  P: 45  R: 11  Sat: 94% RA  Temp: 36.4 ℃

CBG: 6.1

ABCDE: 100% O₂ by mask; 2 large bore IVs; NS 2L IV bolus; CBCD, Rapid Metabolic Panel (RMP), Lactate, ETOH level; acetaminophen and salicylate levels; Venous Blood Gas (VBG); ECG; continuous cardiac monitoring; respiratory therapist and ICU were paged; no signs of trauma in the rapid primary survey (RPS).

HEENT: ⊘ tongue biting. 

CVS: Bradycardia; otherwise unremarkable. 

Resp: AE=AE; bilat. clear fields. 

Abdo: protuberant; BS active; soft; ⊘ peritoneal.

Neuo: Pupils 3mm, symmetric, reactive, ⊘ RAPD; 

moves limbs ✗ 4; ⊘ focal.

Skin: cold extremities; not diaphoretic. 

BP refractory to NS 2 Lit IV bolus; lab results normal; 

ECG: sinus brady @45 with 1st º AV block. 

I/P: beta blocker overdose was suspected; BP responded to glucagon 3mg IV bolus then 3mg/h IV infusion,and D50W 50ml bolus + insulin 60U IV push; insulin infusion 0.5U/kg/h + dextrose 1g/kg/h as D10W were started; CBG repeated q15min; electrolytes repeated q30min; was admited to ICU after initial resuscitation;  

Discussion⁽¹⁾: 

The “toxidrome-oriented” physical examination: 

1. vital signs
2. LOC
3. pupil size and position
4. mucous membranes
5. skin temperature and moisture
6. bowel sounds
7. assessment of motor tone

DDx of hypotension + bradycardia cased by overdose:

1. Beta-blockers (associated w HYPOglycaemia)
2. CCBs (associated w HYPERglycaemia)
3. Digoxin (GI Sx, ECG ▵s)
4. clonidine
5. cholinergics

The empiric use of the so-called “coma cocktail” (dextrose, oxygen, naloxone, and thiamine) is no longer recommended in pt presenting with non-traumatic ↓LOC.

Reference: 

1. http://www.uptodate.com/contents/initial-management-of-the-critically-ill-adult-with-an-unknown-overdose?source=search_result&search=betablocker+poisoning&selectedTitle=2%7E9