Which of the following associations is incorrect: blistering distal dactylitis with Streptococcus (Strep.) pyogenes, hand foot and mouth disease with Coxsackie virus A16, verruca vulgaris with human papilloma virus (HPV) types 6, 11, 16, 18, or hot tub folliculitis with Pseudomonas (P.) aeruginosa?

Answer: Option C is Incorrect

The incorrect association is C: Verruca vulgaris is caused by HPV types 2 and 4, NOT HPV types 6,11,16, and 18. 1, 2

Analysis of Each Association

Option A: Blistering Distal Dactylitis and Strep. Pyogenes - CORRECT

This association is accurate based on standard dermatologic knowledge. Blistering distal dactylitis is a superficial blistering infection of the distal finger pulp caused by Streptococcus pyogenes (Group A Streptococcus).

Option B: Hand Foot and Mouth Disease and Coxsackie Virus A16 - CORRECT

• Hand, foot, and mouth disease is primarily caused by Coxsackie virus A16 and enterovirus 71. 3
• Coxsackie A16 has been isolated from patients with classic HFMD presenting with fever, oral ulcers, and vesicular lesions on hands and feet. 4
• While recent outbreaks have involved Coxsackie A6 causing atypical presentations with widespread vesiculobullous eruptions, the classic association with Coxsackie A16 remains correct. 3, 5

Option C: Verruca Vulgaris and HPV 6,11,16,18 - INCORRECT

• Verruca vulgaris (common wart) is caused by HPV types 2 and 4, NOT types 6,11,16, or 18. 1, 2
• The HPV types listed in option C (6,11,16,18) are associated with different conditions:
  • HPV 6 and 11: Cause genital warts (condyloma acuminatum) and squamous papillomas, accounting for approximately 90% of genital wart cases. 6, 7
  • HPV 16 and 18: High-risk oncogenic types strongly associated with cervical dysplasia, squamous intraepithelial neoplasia, and squamous cell carcinoma. 6, 1
• Verruca vulgaris presents as well-circumscribed, flesh-colored growths with a white pebbly or papillary surface, occurring via autoinoculation from fingers to mouth. 1, 2

Option D: Hot Tub Folliculitis and Pseudomonas Aeruginosa - CORRECT

This association is accurate based on standard infectious disease knowledge. Hot tub folliculitis is a superficial follicular infection caused by Pseudomonas aeruginosa, typically acquired from inadequately chlorinated hot tubs or swimming pools.

Key Clinical Pitfall

Do not confuse the HPV types that cause common warts (verruca vulgaris) with those causing genital warts or malignancy-associated lesions. HPV 2 and 4 cause benign cutaneous warts through autoinoculation, while HPV 6,11,16, and 18 are sexually transmitted types with distinct anatomic distributions and malignant potential. 6, 1, 7