Differentials

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

There may be a history of fever, genital blisters or sores, and lymphadenopathy with first-episode herpes simplex.

The patient may describe previous episodes of genital ulceration.

On physical examination there are typically multiple, painful vesicular or ulcerative lesions on or around the genitals or rectum.

INVESTIGATIONS

Isolation of herpes simplex virus (HSV) from lesions in cell culture confirms the diagnosis, although the sensitivity is low, and decreases as lesions heal.

Viral culture isolates will identify if HSV-1 or HSV-2 is causative.[5]

Increasingly, polymerase chain reaction is supplanting culture as the test of choice to diagnose and type HSV.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Characterised by painful genital ulcers and painful inguinal lymphadenopathy. Lesions of primary syphilis are typically not painful.

Usually occurs in discrete outbreaks.

On physical examination there may be an erythematous papule, pustule, or painful ulcer, as well as painful unilateral inguinal lymphadenopathy (bubo formation), which may rupture.

INVESTIGATIONS

Haemophilus ducreyi is identified on specialist culture medium, which is not widely commercially available and has a sensitivity of <80%.[77]

Polymerase chain reaction testing is up to 100% sensitive but is not universally approved.[77][78]

Therefore a positive diagnosis of chancroid is suggested by the presence of painful genital ulcers with no evidence of syphilis or herpes simplex virus.[5]

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Not preceded by genital ulceration.

However, genital ulceration may be present at the same time as primary HIV infection and the rash associated with the ulceration.

INVESTIGATIONS

Laboratory tests positive for HIV, including antigen (P24 antigen) tests.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Not preceded by genital ulceration.

INVESTIGATIONS

Laboratory tests positive for specific virus.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Skin lesions usually pruritic.

Typical distribution: inter-digital, wrists, nipples, ankles, buttocks.

INVESTIGATIONS

Diagnosis is usually clinical, but skin scrapings and microscopy for Sarcoptes scabiei may be performed.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Skin lesions usually absent on palms and plantar aspects of feet. 

Not associated with signs of systemic infection.

INVESTIGATIONS

Diagnosis is usually clinical.

Skin biopsy can be undertaken to confirm diagnosis.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Skin lesions usually absent on palms and plantar aspects of feet.

Not associated with signs of systemic infection.

INVESTIGATIONS

Diagnosis is usually clinical.

Skin biopsy can be undertaken to confirm diagnosis.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Skin lesions usually absent on palms and plantar aspect of feet. 

Not associated with signs of systemic infection.

INVESTIGATIONS

Diagnosis is usually clinical.

Skin biopsy can be undertaken to confirm diagnosis.

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Pink lumps, in genital and/or peri-anal skin and mucous membranes. Not necessarily confined to opposing membranes.

Not associated with other signs of secondary syphilis (rash, constitutional symptoms, generalised lymphadenopathy).

INVESTIGATIONS

Diagnosis is usually clinical.

Exclusion of syphilis (negative syphilis serology).

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Progressive dementia.

No specific differentiating symptoms and signs compared with neurosyphilis.

Less likely to have a history of possible signs and symptoms of earlier stages of syphilis infection.

INVESTIGATIONS

Exclusion of syphilis (negative syphilis serology).

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Progressive dementia.

Multi-infarct dementia often associated with other evidence of arteriopathy.

Less likely to have a history of possible signs and symptoms of earlier stages of syphilis infection.

INVESTIGATIONS

Exclusion of syphilis (negative syphilis serology).

Use of this content is subject to our disclaimer