Correspondence

Case 5-2003: A 16-Year-Old Girl with a Rash and Chest Pain

N Engl J Med 2004; 350:520-521January 29, 2004

Article

To the Editor:

A patient such as the one described in Case 5-2003 (Feb. 13, 2003, issue),1 who has a rash and a positive test for antinuclear antibodies (in a homogeneous pattern), is usually considered to have systemic lupus erythematosus unless another diagnosis is confirmed. It is reported that the patient's level of total hemolytic complement was normal but that her levels of C3 and C4 were low. These laboratory findings are incompatible, since typically, if the levels of C3, C4, or both are low, the level of total hemolytic complement is also low. Most skin lesions in lupus are photosensitive. The case report indicates that the patient was not exposed to sunlight; however, exposure to fluorescent light can also cause rashes. Usually, I counsel patients to avoid being exposed to the light of fluorescent bulbs, but more important, I advise them to use sunscreen.

Peter H. Schur, M.D.
Harvard Medical School, Boston, MA 02115

1 References

1. 1

   Case Records of the Massachusetts General Hospital (Case 5-2003). N Engl J Med 2003;348:630-637
   Full Text | Web of Science | Medline

Author/Editor Response

Dr. Schur's point about photosensitivity is well taken, and it is true that rashes can be exacerbated by fluorescent light. This patient, a high-school student, was exposed to fluorescent lights daily in school. She has been counseled to wear sunscreen both in school and outdoors. With regard to her complement levels, there have since been quite a few instances in which her total hemolytic complement level has been normal in the presence of slightly decreased levels of C3, C4, or both. This is not an uncommon finding in our laboratory and may be due to the assay used to measure the total hemolytic complement.

Holly Rothermel, M.D.
Massachusetts General Hospital, Boston, MA 02114