| Another common autoimmune rheumatic disease in which the skin is often injured is lupus erythematosus. |
| The differential diagnosis in this case includes secondary syphilis, lepromatous leprosy, cutaneous tuberculosis, and discoid lupus erythematosus. |
| Discoid lupus erythematosus is a chronic disease characterized by inflammatory, scarring lesions. |
| Vasculitis may also occur as a secondary feature in other diseases, such as systemic lupus erythematosus and rheumatoid arthritis. |
| Some of the reported associated systemic diseases include systemic lupus erythematosus, diabetes mellitus, myotonic dystrophy, and chronic active hepatitis. |
| Other collagen diseases, such as progressive systemic sclerosis and systemic lupus erythematosus, are associated with increased incidence of pneumothorax. |
