APEA 3P Exam Comprehensive Predictor Prep for
Pediatrics, Pharmacology & Pathophysiology 2025-2026
A+ Graded
Erythema Migrans (early Lyme disease): Symptoms
Usually appears in 7-14 days after being bitten by a deer tick; range 3-30 days
Target bull's-eye Rash is hot to touch with rough texture. Expanding red rash with central
clearing • Common locations are belt line, axillary area, behind the knees, and groin area •
Positive for flu like symptoms. Lesions and rash resolve within a few weeks with or without
treatment
Erythema Migrans (early Lyme disease): DX
Dx: • First step is enzyme immunoassay (EIA) also knows as ELISA if negative no further
testing needed. If positive confirm with Western Blot test (aka indirect immunofluorescence
assay (IFA) for Borrelia Burgdorferi
1. Enzyme immunoassay
2. western blot test (immunoflurorescence assay/ IFA)
Exam Tip: E before I
Will have increased ESR
Erythema Migrans (early Lyme disease): TX
Doxycycline is always first line for all ages
100 mg BID x 10-21 days
Remove ticks by grasping with tweezers or forceps close to the skin and pulling gently with
steady pressure. After removing the tick, clean area with rubbing alcohol, iodine scrub, or soap
and water. Dispose of the tick by flushing it into the toilet
Tick repellant skin use
DEET
Tick repellant clothing use
Permethrin
Brown Recluse Spider Bite: SX
,• Fever, chills • Nausea and Vomiting • Located in the arms, upper legs, or the trunk • Bitten area
becomes swollen, red, and tender, or can be painless • Blisters appear within 24-48 hours •
Necrotic in center, which kills the tissue
**can be painless
Brown Recluse Spider Bite treatment
Treatment: • Ice packs to wound as the cold inactivates the toxin • Treat like cellulitis of the skin
• Antibiotic ointment at first and watch
Skin lesions
primary skin lesions
Macule Vesicle Papule MVP Size: <1 CM
Macule
Flat, nonpalpable, but visually distinct areas on the skin surface with color different from the
person's normal skin; less than 1 cm
FRECKLE
Vesicle
elevated, raised lesion filled with serous fluid (herpetic lesions)
Papule
palpable solid lesion (acne, moles)
primary skin lesions >1cm in size
Nodule
Plaque
Bullae (Blister)
Pustule
Wheal
Nodule
raised solid lesion (BCC)
Plaque
solid raised lesion with flat top (psoriasis)
Bulla/Bullae
elevated superficial blister filled with serous fluid (2nd degree burn, impetigo)
Pustule
,circumscribed elevated lesion containing pus (acne pustules)
Secondary Skin Lesions-Lichenification
thickening of the epidermis with exaggeration of normal skin due to chronic skin itching
(eczema)
Secondary skin lesions- Scale
flaking skin (psoriasis)
Secondary skin condition-crust
dried exudate (impetigo)
Secondary skin condition-ulceration
eroding of epidermis and dermis (if deep can involve subcutaneous tissue)
Secondary skin condition-scar
permanent fibrotic change following damage to dermis (surgical scars)
Secondary skin condition-keloids/hypertrophic scars
overgrowth of scar tissue (more common in Black and Asian descent)
Rule of 9's
Head and neck = 9%
Upper Ex = 9% each
Lower Ex = 9% each
Front trunk = 18%
Back trunk = 18%
Rule of 9's =-child leg
Chlid one leg=13.5%
One leg adult =18%
Rule of 9's =child head
Child head- 18% (half of adult %)
First degree (superficial):
Red to bright red skin and tenderness/pain
second-degree (partial-thickness) burns
, Painful red skin, bullae (blisters), reddened/weepy skin
--> BLISTERS START AT SECOND DEGREE
third-degree (full-thickness) burns
Pain sensation absent. Pale/white color, charred skin, leather-like texture
Criteria for Burn Center Referral:
Face, hands, feet, genitals, major joints
Electrical burns, lightning burns
Partial thickness burns >10% of total body surface area
Third degree burns in any age group
If pt. has a Sulfa allergy and can't use Silvadene what is the alternative?
Bacitracin, Polysporin/Triple antibiotic cream or ointment
Cellulitis
Bacteria (Gram Positive):
Streptococcus (beta hemolytic strep), Staph aureus (MRSA)
Cellulitis Symptoms:
Diffused pink to red colored skin, warm to touch, and may become abscessed
If red streaks radiating from infection it has spread to lymph nodes (lymphangitis)
Usually within the deep dermis and is poorly demarcated (poor boundaries)
Most common location is the lower legs
-->If pt. has DM and develops cellulitis watch for osteomyelitis
Cellulitis treatment
First line: Abscess/cellulitis is I&D (if <5 cm no PO antibiotic needed) • Check for tetanus
vaccine status
Nonpurulent: Cephalexin (Keflex) 500 mg or Dicloxacillin q 6 hours for 5-10 days
Purulent (MRSA): Wound culture o Follow up in 48 hours Bactrim BS BID x 10 days o If you
suspect osteomyelitis order an MRI
If allergic to Penicillin: Azithromycin (Z-Pack x 5 days)
Erysipelas:
Bacteria: Group A Streptococcus
Located: • Involves upper dermis and superficial lymphatics • Found on the cheeks and shins
Erysipelas: Symptoms
Pediatrics, Pharmacology & Pathophysiology 2025-2026
A+ Graded
Erythema Migrans (early Lyme disease): Symptoms
Usually appears in 7-14 days after being bitten by a deer tick; range 3-30 days
Target bull's-eye Rash is hot to touch with rough texture. Expanding red rash with central
clearing • Common locations are belt line, axillary area, behind the knees, and groin area •
Positive for flu like symptoms. Lesions and rash resolve within a few weeks with or without
treatment
Erythema Migrans (early Lyme disease): DX
Dx: • First step is enzyme immunoassay (EIA) also knows as ELISA if negative no further
testing needed. If positive confirm with Western Blot test (aka indirect immunofluorescence
assay (IFA) for Borrelia Burgdorferi
1. Enzyme immunoassay
2. western blot test (immunoflurorescence assay/ IFA)
Exam Tip: E before I
Will have increased ESR
Erythema Migrans (early Lyme disease): TX
Doxycycline is always first line for all ages
100 mg BID x 10-21 days
Remove ticks by grasping with tweezers or forceps close to the skin and pulling gently with
steady pressure. After removing the tick, clean area with rubbing alcohol, iodine scrub, or soap
and water. Dispose of the tick by flushing it into the toilet
Tick repellant skin use
DEET
Tick repellant clothing use
Permethrin
Brown Recluse Spider Bite: SX
,• Fever, chills • Nausea and Vomiting • Located in the arms, upper legs, or the trunk • Bitten area
becomes swollen, red, and tender, or can be painless • Blisters appear within 24-48 hours •
Necrotic in center, which kills the tissue
**can be painless
Brown Recluse Spider Bite treatment
Treatment: • Ice packs to wound as the cold inactivates the toxin • Treat like cellulitis of the skin
• Antibiotic ointment at first and watch
Skin lesions
primary skin lesions
Macule Vesicle Papule MVP Size: <1 CM
Macule
Flat, nonpalpable, but visually distinct areas on the skin surface with color different from the
person's normal skin; less than 1 cm
FRECKLE
Vesicle
elevated, raised lesion filled with serous fluid (herpetic lesions)
Papule
palpable solid lesion (acne, moles)
primary skin lesions >1cm in size
Nodule
Plaque
Bullae (Blister)
Pustule
Wheal
Nodule
raised solid lesion (BCC)
Plaque
solid raised lesion with flat top (psoriasis)
Bulla/Bullae
elevated superficial blister filled with serous fluid (2nd degree burn, impetigo)
Pustule
,circumscribed elevated lesion containing pus (acne pustules)
Secondary Skin Lesions-Lichenification
thickening of the epidermis with exaggeration of normal skin due to chronic skin itching
(eczema)
Secondary skin lesions- Scale
flaking skin (psoriasis)
Secondary skin condition-crust
dried exudate (impetigo)
Secondary skin condition-ulceration
eroding of epidermis and dermis (if deep can involve subcutaneous tissue)
Secondary skin condition-scar
permanent fibrotic change following damage to dermis (surgical scars)
Secondary skin condition-keloids/hypertrophic scars
overgrowth of scar tissue (more common in Black and Asian descent)
Rule of 9's
Head and neck = 9%
Upper Ex = 9% each
Lower Ex = 9% each
Front trunk = 18%
Back trunk = 18%
Rule of 9's =-child leg
Chlid one leg=13.5%
One leg adult =18%
Rule of 9's =child head
Child head- 18% (half of adult %)
First degree (superficial):
Red to bright red skin and tenderness/pain
second-degree (partial-thickness) burns
, Painful red skin, bullae (blisters), reddened/weepy skin
--> BLISTERS START AT SECOND DEGREE
third-degree (full-thickness) burns
Pain sensation absent. Pale/white color, charred skin, leather-like texture
Criteria for Burn Center Referral:
Face, hands, feet, genitals, major joints
Electrical burns, lightning burns
Partial thickness burns >10% of total body surface area
Third degree burns in any age group
If pt. has a Sulfa allergy and can't use Silvadene what is the alternative?
Bacitracin, Polysporin/Triple antibiotic cream or ointment
Cellulitis
Bacteria (Gram Positive):
Streptococcus (beta hemolytic strep), Staph aureus (MRSA)
Cellulitis Symptoms:
Diffused pink to red colored skin, warm to touch, and may become abscessed
If red streaks radiating from infection it has spread to lymph nodes (lymphangitis)
Usually within the deep dermis and is poorly demarcated (poor boundaries)
Most common location is the lower legs
-->If pt. has DM and develops cellulitis watch for osteomyelitis
Cellulitis treatment
First line: Abscess/cellulitis is I&D (if <5 cm no PO antibiotic needed) • Check for tetanus
vaccine status
Nonpurulent: Cephalexin (Keflex) 500 mg or Dicloxacillin q 6 hours for 5-10 days
Purulent (MRSA): Wound culture o Follow up in 48 hours Bactrim BS BID x 10 days o If you
suspect osteomyelitis order an MRI
If allergic to Penicillin: Azithromycin (Z-Pack x 5 days)
Erysipelas:
Bacteria: Group A Streptococcus
Located: • Involves upper dermis and superficial lymphatics • Found on the cheeks and shins
Erysipelas: Symptoms
