Human Papilloma Virus

Question 1

Aetiology of HPV infection

Answer 1

ds-DNA virus
Transmission: direct contact with HPV lesions/contaminates surfaces/auto-inoculation
Primary target of HPV = basal keratinocytes
Normally, the virus is unable to gain entry to these cells due to overlying differentiated cell layers, but trauma e.g. abrasion disrupts this barrier and allows virus entry

Genital warts: HPV 6 and 11
Cervical cancer: HPV 16 and 18

Question 2

Risk factors for HPV infection

Answer 2

Early pregnancy
Smoking
Immunocompromise e.g. from HIV infection
Age 45-49
Long-term and combined contraceptive use
Not attending smear screening
Young age at first intercourse

Question 3

Symptoms of HPV infection

Answer 3

Asymptomatic

OR

Genital warts
- Appear within weeks to months after exposure to HPV
- Painless of painful
- Friable, pruritic
- Bleeding
Terminal haematuria or abnormal stream of urine

Question 4

Differentials for genital warts caused by HPV

Answer 4

Condyloma latum
Molluscum contagiosum
Pearly penile papules
Seborrheic keratoses
Skin tags

Question 5

Signs of HPV infection on examination

Answer 5

Genital warts:
Verrucous fleshy papules that may coalesce into plaques
Size ranges from a few mm to cm
Site: anogenital or genital area, including on mucosal surfaces
Colour: whitish to flesh-coloured to hyperpigmented to erythematous

Question 6

Investigations for HPV infection

Answer 6

Clinical diagnosis

If uncertain:
Swab: +ve
Biopsy: ?malignancy
Anoscopy: for recurrent warts
Urethroscopy: for urinary symptoms

Question 7

Management for genital warts caused by HPV

Answer 7

Podophyllotoxin topical, patient-applied therapy
- Apply to affected area twice daily for 3 days, followed by 4 days of no treatment → repeat for up to 4 cycles
- Arrests cell division in cell mitosis
Cryotherapy
Trichloroacetic acid and bichloroacetic acid (for small, moist genital warts)
Surgical excision
CO2 laser ablation
Electrodessication
Photodynamic therapy

Question 8

Management for internal warts (vagina, intra-anal, urethral)

Answer 8

Cryotherapy with liquid nitrogen
Surgical removal
Trichloroacetic acid and bichloroacetic acid (for small, moist genital warts)

Question 9

Prognosis for HPV infection

Answer 9

No cure for genital warts - goal of treatment is to eliminate visible lesions
10% to 30% of genital warts resolve in 3 months of onset without treatment
High recurrence rates with trichloroacetic acid