Seborrheic dermatitis

Although seborrheic dermatitis is very common, you should offer an HIV test in the event of sudden onset, or unusual or therapy-resistant presentations. European research found an HIV prevalence of 2% in patients presenting with seborrheic dermatitis 27 and European guidance strongly recommends offering an HIV test to these patients. Recent onset of seborrheic dermatitis, dry skin or itchy folliculitis raises the index of suspicion for HIV.

Seborrhoeic dermatitis (Simon Barton)

Seborrhoeic eczema of axilla (Henry de Vries)

Seborroeic eczema - perianal and scrotal (Henry de Vries)

Seborroeic eczema on trunk and limb (Henry de Vries)

Seborrheic dermatitis of the face (Colm O'Mahony)

Hypopigmented and squamous sharply demarcated plaques on the back of a patient with psoriasis vulgaris and skin type 5 (Henry de Vries)

Erythemato-squamous sharply demarcated plaques on the shins of a patient with psoriasis vulgaris and skin type 2 (Henry de Vries)

Erythematous sharply demarcated plaque on the elbow of a patient with psoriasis vulgaris and skin type 2 (Henry de Vries)

Extensive psoriasis vulgaris on the back of a patient with skin type 5 (Henry de Vries)

Generalized erythroderma of trunk and arms in a patient with psoriasis vulgaris (Henry de Vries)

Perianal psoriasis (Lewis Lau)


HIV may exacerbate pre-existing psoriasis or cause it to appear for the first time. European guidance recommends offering HIV testing when psoriasis is severe, atypical or recalcitrant. It is also important to consider the risk of pre-existing HIV infection and offer a test if in doubt, before prescribing immune-suppressive therapy for psoriasis.

Fungal, viral and bacterial infections


  • Tinea (faciei, corporis, crurus, pedis)
  • Tinea unguium (onychomycosis)
  • Pityriasis


  • Human papilloma virus (warts)
  • Molluscum contagiosum
  • Epstein Barr Virus


  • Staphylococcal infections
  • Impetigo
  • Folliculitis
  • Cellulitis
  • Mycobacterial infections

Bacterial: Demodex folliculitis (Henry de Vries)

Bacterial: Mycobacterial infection of scrotal skin (Henry de Vries)

Bacterial: Pruritic papular folliculitis of HIV (Henry de Vries)

Viral: Extensive molluscum contagiosum on penis (Henry de Vries)

Viral: Molluscum contagiosum along jaw line (Henry de Vries)

Viral: Molluscum contagiosum on face (Henry de Vries)

Viral: Vulval molluscum contagiosum and warts in an HIV-positive patient (Angela Robinson)

Fungal: Onychomycosis pedis in an HIV positive patient (Henry de Vries)

Bacterial: Pruritic papular eruption of HIV (Henry de Vries)

Bacterial: Late presentation of HIV in a patient with severe impetigo (Colm O'Mahony)

Acne vulgaris (Henry de Vries)

Alopecia areata (Henry de Vries)

Alopecia diffusa (Henry de Vries)

Crusted scabies - scrotum (Henry de Vries)

Crusted scabies on feet (Henry de Vries)

Crusted scabies on upper thigh (Henry de Vries)

Eosinophilic folliculitis (Henry de Vries)

Exanthema of HIV (Henry de Vries)

Foot of a patient with vasculitis. Visible are serpiginous ecchymoses and ulcers covered with black and yellow necrosis (Henry de Vries)

Ichthyosis lamellaris (Henry de Vries)

Pruritis of the leg (Henry de Vries)

Hyperemic papules and plaques surrounded by a pale zone on the lower arm of a patient with urticaria factitia. This is also known as the tri-colour sign in which the actual erythematous coloured urtica is caused by vasodilatation, the pale coloured zone by reactive vasoconstriction and the normal (third) colour is found on the unaffected skin. (Henry de Vries)

Xerosis cutis (Henry de Vries)

Other common skin conditions

Severe or recalcitrant presentations of the following skin conditions should also prompt consideration of HIV:

  • Pruritus
  • Exanthema
  • Eosinophillic foliculitis
  • Acne (vulgaris/rosacea)
  • Vasculitis
  • Urticaria
  • Ichthyosis
  • Xerosis
  • Alopecia (diffuse and areata)
  • Infestations (scabies)


A number of cancers, including skin and genital cancers, are more common in people living with HIV than in the general population. HIV testing should be considered in patients presenting with:

  • Cutaneous lymphoma
  • Systemic lymphoma
  • Genital carcinoma

Perianal squamous cell carcinoma in an HIV-positive man who has sex with men (Henry de Vries)

B-cell lymphoma in HIV patient (Colm O'Mahony)

Penile intraepithelial neoplasia full thickness (Lewis Lau)

When to test for HIV / Part 3

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