Lupus erythematosus

Photosensitivity is the amount to which an object reacts upon receiving photons especially in visible light. Photosensitivity is a known symptom of lupus, but its relationship to and influence on other aspects of the disease remain to be defined.[4] Causes of photosensitivity may include:

• change in autoantibody location
• cytotoxicity
• induction of apoptosis with autoantigens in apoptotic blebs
• upregulation of adhesion molecules and cytokines
• induction of nitric oxide synthase expression
• ultraviolet-generated antigenic DNA

Lupus can develop in people at any age, but it does most commonly at ages 15 to 44, with varying results. Typically, the manifestation of the disease tends to be more acute in those of younger age. Women are more likely to get it than men. Patients with juvenile-onset lupus are more vulnerable to mucocutaneous manifestations of the disease (alopecia, skin rash, and ulceration of the mucus membranes) than any other age group, and they are also more susceptible to evaluation of pulmonary artery pressure.[7] However, patients with late-onset lupus have a much higher mortality rate. Nearly 50% of those with late-onset lupus die of their condition. Women who are of childbearing age are also particularly at risk.[8]

Substantial data have been found to indicate that certain ethnic populations could be more at risk for lupus erythematosus and to have a better or worse prognosis. Asian, African, and Native Americans are more likely to get lupus than Caucasians. Caucasians seem generally to have a milder manifestation of the disease. Their survival rates after five years were typically around 94–96%, while patients of African and some Asian ethnicities had survival rates closer to 79–92%. The only documented ethnic group that had a higher survival rate than Caucasians was Koreans, who had survival rates nearer to 98%. Among Caucasians, the most common causes of death were complications involving the cardiovascular system, the respiratory system, and malignancies.[9][10] Atherosclerotic cardiovascular disease is more prevalent in African Americans with lupus than in Caucasians with lupus.[11]

Lupus erythematosus may manifest as systemic disease or in a purely cutaneous form also known as incomplete lupus erythematosus. Lupus has four main types:

• systemic
• discoid
• drug-induced
• neonatal

Of these, systemic lupus erythematosus (also known as SLE) is the most common and serious form.

A more thorough categorization of lupus includes the following types:[15][16]

• acute cutaneous lupus erythematosus
• subacute cutaneous lupus erythematosus
• discoid lupus erythematosus (chronic cutaneous)
  • • childhood discoid lupus erythematosus
    • generalized discoid lupus erythematosus
    • localized discoid lupus erythematosus
  • chilblain lupus erythematosus (Hutchinson)
  • lupus erythematosus-lichen planus overlap syndrome
  • lupus erythematosus panniculitis (lupus erythematosus profundus)
  • tumid lupus erythematosus
  • verrucous lupus erythematosus (hypertrophic lupus erythematosus)
  • cutaneous lupus mucinosis
• complement deficiency syndromes
• drug-induced lupus erythematosus
• neonatal lupus erythematosus
• systemic lupus erythematosus

• An estimated 5 million people worldwide have some form of lupus disease.[21]
• 70% of lupus cases diagnosed are systemic lupus erythematosus.[21]
• 20% of people with lupus will have a parent or sibling who already has lupus or may develop lupus.[21]
• about 5% of the children born to individuals with lupus will develop the illness.[21]

• Females in the UK are seven times more likely to be diagnosed with SLE than males.[22]
• The estimated number of females in the UK with SLE is 21,700, and the number of males is 3000 — a total of 24,700, or 0.041% of the population.[22]
• SLE is more common amongst certain ethnic groups than others, especially those of African origin.[22]

• Lupus occurs from infancy to old age, with peak occurrence between ages 15 and 40.[18]
• Lupus affects females in the US 6 to 10 times more often than males.[18]
• Prevalence data are limited. Estimates vary and range from 1.8 to 7.6 cases per 100,000 persons per year in parts of the continental United States.[18]