Chronic cutaneous lupus erythematosus, also known as Discoid
lupus (DLE) - about 15% of all lupus patients are classified
as having DLE, but patients with SCLE or SLE may also have discoid
lesions.
It is diagnosed when a patient with a discoid lupus rash (confirmed
by skin biopsy) does not fulfill the ACR criteria for SLE.
15 to 30% of all SLE patients have DLE lesions.
5 - 10% of all SLE patients will have DLE as their presenting
complaint.
DLE occurs most commonly between the ages of 20 and 40.
The female to male ratio is about 3:2, as opposed to SLE where
the ratio is 9:1.
The DLE lesion is usually raised or flat, red, with well-defined
borders, they may itch.
DLE is often scarring, and in larger lesions (smaller lesions
grow together to make these) can be very disfiguring.
Sun-exposed areas are most often affected: the face, the ears,
the scalp, the 'V' of the neck, and the top-side of the forearm.
Discoid lupus can appear similar to other skin lesions, e.g. rosacea,
fungal infections, sarcoidosis, seborrhea, dermatomyositis.
Aching joints & other constitutional symptoms are found in
10-20% of DLE patients.
'Localised DLE' is a term used to describe discoid lesions appearing
only above the neck.
'Generalised DLE' implies lesions above & below the neck.
This form has a 10% chance of developing into SLE.
DLE is most commonly treated with antimalarials, topical injections,
& in severe cases, corticosteroids.