Involvement of scalp and nails in lupus erythematosus.

Lupus erythematosus (LE) is a systemic autoimmune disorder associated with polyclonal B-cell activation resulting in diverse patterns of autoantibody production and a heterogeneous clinical expression constituting a spectrum extending from limited cutaneous disease to life-threatening systemic manifestations. For daily clinical practice, the characteristics of cutaneous lupus erythematosus (CLE) have been well defined in terms of morphology, and clinical and laboratory criteria are available for the classification as systemic lupus erythematosus (SLE). The many different types of skin lesions encountered in patients with LE have been classified into those that are histologically specific for LE and those that are not. While LE non-specific skin lesions on their own do not enable a diagnosis of LE, they can be important reflections of underlying SLE disease activity. This also applies to the involvement of the scalp and nails. Finally, it must be kept in mind that LE patients may also develop drug-related, or other unrelated common disorders of the hair and nails that do not reflect LE disease activity.