The Incorrect Association is C: Verruca Vulgaris and HPV 6,11,16,18
The correct answer is C because verruca vulgaris (common warts) is caused by HPV types 2 and 4, not types 6,11,16, or 18. 1
Analysis of Each Association
A. Blistering Distal Dactylitis: Streptococcus pyogenes - CORRECT
- Blistering distal dactylitis is characteristically caused by group A beta-hemolytic Streptococcus (Streptococcus pyogenes) 2
- Less commonly, Staphylococcus aureus and Staphylococcus epidermidis may be causative organisms 2
- This presents as a localized infection involving the volar fat pad of the distal phalanx with fluid-filled blisters 2, 3
B. Hand, Foot, and Mouth Disease: Coxsackievirus A16 - CORRECT
- Hand, foot, and mouth disease is primarily caused by Coxsackievirus A16 and enterovirus 71 4
- The disease presents with fever, painful papules and blisters over extremities and genitalia, plus oral ulceration 4
- Recent outbreaks have also been associated with Coxsackievirus A6, which causes more extensive and atypical presentations 4, 5, 6
C. Verruca Vulgaris: HPV 6,11,16,18 - INCORRECT
- Verruca vulgaris is caused by HPV types 2 and 4, NOT types 6,11,16, or 18 1, 7
- Common warts present as well-circumscribed, flesh-colored growths with a white pebbly or papillary surface 1, 7
- These occur via autoinoculation from fingers to mouth 1, 7
The HPV types listed in option C actually cause different conditions:
- HPV 6 and 11: Cause genital warts (condyloma acuminatum) and squamous papillomas, accounting for approximately 90% of genital wart cases 8, 1, 9
- HPV 16 and 18: High-risk oncogenic types strongly associated with cervical dysplasia, squamous intraepithelial neoplasia, and squamous cell carcinoma 8, 1
D. Hot Tub Folliculitis: Pseudomonas aeruginosa - CORRECT
- Hot tub folliculitis is correctly associated with Pseudomonas aeruginosa infection
- This occurs from exposure to contaminated water in hot tubs, whirlpools, and swimming pools
Key Clinical Pitfall
The critical error to avoid is confusing cutaneous HPV types (2,4) that cause benign common warts with sexually transmitted HPV types (6,11,16,18) that have distinct anatomic distributions and different malignant potentials. 1 HPV 2 and 4 cause benign cutaneous warts through autoinoculation, while HPV 6,11,16, and 18 are sexually transmitted types with genital/anogenital involvement. 1