Also known as … Capillaritis
Pigmented Purpuric Dermatosis is an uncommon condition that affects all races and ages. It usually manifests as small or large patches of cayenne pepper coloured spots and pigmentation. The skin rash is usually found on the lower limbs but may also involve the trunk.
The cause of pigmented purpuric dermatosis is currently unknown. Several risk factors have been implicated including venous disease, capillary fragility, certain drugs and allergy to certain food colourings and dyes. Basic science and clinical research is currently underway to investigate the cause of this condition and explore effective treatments.
There are several different forms of pigmented purpuric dermatosis but all these forms share some common features. The key feature is the cayenne pepper coloured spots that can join up to create larger patches. The cayenne pepper spots indicate fresh lesions. The spots are fixed and do not disappear with pressure. Spots or larger patches of brown pigmentation indicate older lesions. Except for one form PPD is usually not itchy and not painful.
The diagnosis is usually made by the dermatologist examining the individual. A skin biopsy will confirm the diagnosis.
Treatment of pigmented purpuric dermatosis depends on the underlying condition. Treatment of the underlying venous disease will improve the rash but will not result in complete resolution. Any medication that is found to be the cause should be stopped. Specialised blood tests and even allergy testing may be required to find the cause.
This information has been written by Associate Professor Kurosh Parsi