Lupus erythematosushttps://en.wikipedia.org/wiki/Lupus_erythematosus
Lupus erythematosus is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Women of childbearing age are affected about nine times more often than men. While it most commonly begins between the ages of 15 and 45.

The cause of lupus erythematosus is not clear. Among identical twins, if one is affected there is a 24% chance the other one will be as well. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increase the risk.

Treatments may include NSAIDs, corticosteroids, immunosuppressants, hydroxychloroquine, and methotrexate. Although corticosteroids are effective, long-term use results in side effects.

  • Unlike this photo, it is more characteristic for the disorder to occur on the face than on the torso.
  • It appears as a slightly purplish erythema.
  • The butterfly rash that typically appears on the face.
  • It usually appears in sun-exposed areas and looks like a scar.
  • Discoid lupus erythematosus
  • Facial erysipelas
References Cutaneous Lupus Erythematosus: Progress and Challenges 32248318 
NIH
Diagnostic challenges exist in better defining cutaneous lupus erythematosus (CLE) as an independent disease distinct from systemic lupus erythematosus with cutaneous features and further classifying CLE based on clinical, histological, and laboratory features. Recent mechanistic studies revealed more genetic variations, environmental triggers, and immunologic dysfunctions that are associated with CLE. Drug induction specifically has emerged as one of the most important triggers for CLE. Treatment options include topical agents and systemic therapies, including newer biologics such as belimumab, rituximab, ustekinumab, anifrolumab, and BIIB059 that have shown good clinical efficacy in trials.
 Cutaneous Lupus Erythematosus: Diagnosis and treatment 24238695 
NIH
Cutaneous lupus erythematosus (CLE) encompasses a wide range of dermatologic manifestations, which may or may not be associated with the development of systemic disease. Cutaneous lupus is divided into several sub-types, including acute CLE (ACLE), sub-acute CLE (SCLE) and chronic CLE (CCLE). CCLE includes discoid lupus erythematosus (DLE), LE profundus (LEP), chilblain cutaneous lupus and lupus tumidus.
 Cutaneous Lupus Erythematosus: An Update on Pathogenesis and Future Therapeutic Directions 37140884 
NIH
Lupus erythematosus comprises a spectrum of autoimmune diseases that may affect various organs (systemic lupus erythematosus [SLE]) or the skin only (cutaneous lupus erythematosus [CLE]). Typical combinations of clinical, histological and serological findings define clinical subtypes of CLE, yet there is high interindividual variation. Skin lesions arise in the course of triggers such as ultraviolet (UV) light exposure, smoking or drugs