Subacute cutaneous lupus erythematosus

 Subacute cutaneous lupus erythematosus

This is less severe than acute SLE, but is also often associated with systemic disease. Its cause is unknown, but probably involves an antibody-dependent cellular cytotoxic attack on basal cells by K cells bridged by antibody to Ro (SS-A) antigen.

Presentation

Patients with subacute cutaneous LE are often photo-sensitive. The skin lesions are sharply marginated scaling psoriasiform plaques, sometimes annular, lying on the forehead, nose, cheeks, chest, hands and extensor surfaces of the arms. They tend to be sym-metrical and are hard to tell from discoid LE, or SLE with widespread discoid lesions.

Course

As in SLE, the course is prolonged. The skin lesions are slow to clear but, in contrast to discoid LE, do so with little or no scarring.

Complications

Systemic disease is frequent, but not usually serious. Children born to mothers who have, or have had, this condition are liable to neonatal LE with transient annular skin lesions and permanent heart block.

Differential diagnosis

The morphology is characteristic, but lesions can be mistaken for psoriasis or widespread discoid LE. Annular lesions may resemble tinea corporis  or figurate erythemas.

Investigations

Patients with subacute cutaneous LE should be evaluated in the same way as those with acute SLE, although deposits of immunoglobulins in the skin and antinuclear antibodies in serum are present less often. Many have antibodies to the cytoplasmic antigen Ro (SS-A).

Treatment

Subacute cutaneous LE does better with antimalarials, such as hydroxychloroquine, than acute SLE. Oral retinoids are also effective in some cases. Systemic steroids may be needed too.

Comments

Post a Comment

Popular posts from this blog

Dermatophyte infections (ringworm) - Fungal infections

Image
  Fungal infections Dermatophyte infections (ringworm) Cause Three genera of dermatophyte fungi cause tinea infec-tions (ringworm). •     Trichophyton askin, hair and nail infections.   •     Microsporum askin and hair.   •     Epidermophyton askin and nails.   Dermatophytes invade keratin only, and the inflam-mation they cause is due to metabolic products of the fungus or to delayed hypersensitivity. In gen-eral, zoophilic fungi (those transmitted to humans by animals) cause a more severe inflammation than anthropophilic ones (spread from person to person). Presentation and course This depends upon the site and on the strain of fungus involved. Tinea pedis (athlete’s foot) This is the most common type of fungal infection in humans. The sharing of wash places (e.g. in show-ers) and of swimming pools, predisposes to infection; occlusive footwear encourages relapses. Most cases are caused by one of three organisms: Trichophy...
Read more

Dermatoses precipitated or perpetuated by emotional factors

  Dermatoses precipitated or perpetuated by emotional factors Popular candidates for inclusion in this group of diseases are psoriasis, urticaria, atopic eczema, pom-pholyx, discoid eczema, alopecia areata, lichen sim-plex and lichen planus. Fancy rather than fact still rules here, but a scientific basis for these effects is gradually being established. For example, in psoriasis, stress increases the neuropeptide content of lesions, with a concomitant drop in the activity of enzymes that degrade neuropeptides, especially mast-cell chy-mase. In addition, the blood concentrations of certain neuromediators, especially  β -endorphin, changes during exacerbations. Yet an aura of doubt lingers onafor a variety of reasons. The concept of stress is not a simple one, and the terms in which it is discussed are sometimes used rather vaguely. Each type of stress may well provoke its own pattern of response. For this reason many investigators have preferred to record damaging life events r...
Read more

The hair: Classification

Image
  Classification Hairs are classified into three main types. 1    Lanugo hairs . Fine long hairs covering the fetus,but shed about 1 month before birth. 2  Vellus hairs . Fine short unmedullated hairs cover-ing much of the body surface. They replace the lanugo hairs just before birth. 3  Terminal hairs. Long coarse medullated hairs seen, for example, in the scalp or pubic regions. Their growth is often influenced by circulating androgen levels. Terminal hairs convert to vellus hairs in male pattern alopecia, and vellus to terminal hairs in hirsutism. The lips, glans penis, labia minora, palms and soles remain free of hair follicles.  
Read more