This is a symptom of a serious disease causing occlusion of small arteries usually in the leg causing skin bleeding and loss of circulation.
The most common diseases causing retiform purpura:
- DIC, TTP, Warfarin or Heparin induced thrombosis
- Bacterial infections, endocarditis, atrial myxoma
Treatment is to treat the cause
Erythema MultiformeIt is an immune reaction skin eruption characterized by the presence of target lesions with outer red ring and inner pale ring. It has 2 types:
- Erythema Multiforme Minor: the rash typically appears on dace and limbs, it does not affect the mucous membranes, no fever or joint pain, usual tigger is Herpes or Mycoplasma infection or drug reaction.
- Erythema Multiforme Major: it is characterized by the same rash + mucosal involvement (oral ulcers), fever, malaise, joint pain and swelling.
Stevens-Johnson Syndrome (SJS) & Toxic Epidermal Necrolysis (TEN)
- This is a very serious generalized skin and mucous membranes condition that complicates most of the time a drug use causing a widespread blistering and ulceration
- It is called SJS if only 10% of the body surface is affected.
- It is called TEN if it is >30%
- It is called SJS/TEN if it is >10% and <30%
- Symptoms start 1-3 weeks after drug ingestion onset
- It may start with fever and Flu symptoms
- Unlike Erythema Multiforme it tends to affect face and trunk
- Internal organs may be involved
Treatment: IV Steroids or Immunoglobulin + wounds care in ICU/Burn unit
Drug Hypersensitivity Syndrome
- It is a severe life threatening medication reaction
- The most encountered culprit is Sulfa, Allopurinol and seizure Meds.
- Symptoms start 2-6 weeks after exposure with fever and Flu symptoms followed by rash and skin burning pain
- Rash start on face and spread to trunk (measles like eruption)
- Eventually the face will be swollen and red (the hallmark)
- Internal organs involvement may occur
- Mucous membranes can be affected but less common than SJS/TEN
- Treatment: Stop the drug and IV steroids with taper over weeks to months
- It causes diffuse redness of 80 to 90% of the body surface
- It is usually associated with itching , swelling, erosions, scaling and swollen lymph nodes.
- It can be idiopathic or worsening of atopic dermatitis Orr Psoriasis
Treatment involves IV hydration and Steroids and treatment of infection.
Acute Generalized Exanthematous Pustulosis
- It is rapid onset yellow blisters(pustules)
- The most common cause is antibiotic
- Most are self limited and resolves in 2 weeks
Treatment: stop the antibiotic, consider Steroids use