I-HUMAN CASE STUDY: ALLERGIC CONTACT
DERMATITIS (POISON OAK) IN A 25-YEAR-OLD
FEMALE LATEST EDITION 2026-2027 CLINICAL
REVIEW BY LAUREN PALUCH WITH ALL
CORRECT QUESTIONS AND ANSWERS
RANKED A+
,CASE OVERVIEW
A 25-year-old female presents to the clinic with a pruritic rash that developed 2 days after
hiking. She reports:
• Intense itching (worse at night)
• Red, raised skin lesions
• Linear streaks of rash on arms and legs
• Recent exposure to wooded area with plants
No fever, no respiratory symptoms, and no new medications.
HISTORY TAKING (MCQs)
1. What is the MOST important question to ask first?
A. “Have you changed your laundry detergent?”
B. “Did you recently spend time outdoors or in wooded areas?”
C. “Do you have a history of asthma?”
D. “Have you been stressed recently?”
Answer: B
Rationale:
Poison oak dermatitis is caused by urushiol exposure from plants outdoors. Exposure history is
the priority clue.
2. Which symptom is MOST characteristic of allergic contact dermatitis?
A. Painful pustules
B. Non-pruritic vesicles
C. Intense pruritus with linear rash
D. Flaky, silvery plaques
Answer: C
,Rationale:
Poison oak causes itchy, linear, vesicular rash due to plant brushing against skin.
3. What additional exposure history is MOST relevant?
A. Pet exposure
B. New food intake
C. Hiking or outdoor plant contact
D. Sexual activity
Answer: C
Rationale:
Urushiol oil is found in poison oak, ivy, and sumac in outdoor environments.
PHYSICAL ASSESSMENT
4. Which finding is MOST expected on exam?
A. Urticarial wheals
B. Honey-colored crusts
C. Linear erythematous vesicles
D. Petechial rash
Answer: C
Rationale:
Allergic contact dermatitis typically presents with linear vesicles and erythema.
5. What distribution pattern supports poison oak exposure?
A. Symmetrical trunk rash
B. Dermatomal distribution
C. Linear streaks on exposed skin
D. Palms and soles only
Answer: C
, Rationale:
Plant contact produces streak-like lesions where skin brushed against leaves.
DIFFERENTIAL DIAGNOSIS
6. Which condition must be ruled out first?
A. Psoriasis
B. Cellulitis
C. Herpes zoster
D. Seborrheic dermatitis
Answer: B
Rationale:
Cellulitis is bacterial and requires urgent treatment; must be ruled out if redness is present.
7. Which feature helps differentiate allergic contact dermatitis from infection?
A. Fever
B. Pruritus
C. Warm skin
D. Swelling
Answer: B
Rationale:
Itching is dominant in allergic reactions; infections are more painful than itchy.
PATHOPHYSIOLOGY
8. Poison oak dermatitis is classified as:
A. Type I hypersensitivity
B. Type II hypersensitivity
DERMATITIS (POISON OAK) IN A 25-YEAR-OLD
FEMALE LATEST EDITION 2026-2027 CLINICAL
REVIEW BY LAUREN PALUCH WITH ALL
CORRECT QUESTIONS AND ANSWERS
RANKED A+
,CASE OVERVIEW
A 25-year-old female presents to the clinic with a pruritic rash that developed 2 days after
hiking. She reports:
• Intense itching (worse at night)
• Red, raised skin lesions
• Linear streaks of rash on arms and legs
• Recent exposure to wooded area with plants
No fever, no respiratory symptoms, and no new medications.
HISTORY TAKING (MCQs)
1. What is the MOST important question to ask first?
A. “Have you changed your laundry detergent?”
B. “Did you recently spend time outdoors or in wooded areas?”
C. “Do you have a history of asthma?”
D. “Have you been stressed recently?”
Answer: B
Rationale:
Poison oak dermatitis is caused by urushiol exposure from plants outdoors. Exposure history is
the priority clue.
2. Which symptom is MOST characteristic of allergic contact dermatitis?
A. Painful pustules
B. Non-pruritic vesicles
C. Intense pruritus with linear rash
D. Flaky, silvery plaques
Answer: C
,Rationale:
Poison oak causes itchy, linear, vesicular rash due to plant brushing against skin.
3. What additional exposure history is MOST relevant?
A. Pet exposure
B. New food intake
C. Hiking or outdoor plant contact
D. Sexual activity
Answer: C
Rationale:
Urushiol oil is found in poison oak, ivy, and sumac in outdoor environments.
PHYSICAL ASSESSMENT
4. Which finding is MOST expected on exam?
A. Urticarial wheals
B. Honey-colored crusts
C. Linear erythematous vesicles
D. Petechial rash
Answer: C
Rationale:
Allergic contact dermatitis typically presents with linear vesicles and erythema.
5. What distribution pattern supports poison oak exposure?
A. Symmetrical trunk rash
B. Dermatomal distribution
C. Linear streaks on exposed skin
D. Palms and soles only
Answer: C
, Rationale:
Plant contact produces streak-like lesions where skin brushed against leaves.
DIFFERENTIAL DIAGNOSIS
6. Which condition must be ruled out first?
A. Psoriasis
B. Cellulitis
C. Herpes zoster
D. Seborrheic dermatitis
Answer: B
Rationale:
Cellulitis is bacterial and requires urgent treatment; must be ruled out if redness is present.
7. Which feature helps differentiate allergic contact dermatitis from infection?
A. Fever
B. Pruritus
C. Warm skin
D. Swelling
Answer: B
Rationale:
Itching is dominant in allergic reactions; infections are more painful than itchy.
PATHOPHYSIOLOGY
8. Poison oak dermatitis is classified as:
A. Type I hypersensitivity
B. Type II hypersensitivity
