Monday 14 July 2003
DSG1 is an autoantigen in pemphigus foliaceus
mutations of DSG1 cause type I striate keratosis palmoplantaris (PPKS type1) (MIM.148700)
toxic DSG1 inactivation in staphylococcal infections
- bullous impetigo
- staphylococcal scalded skin syndrome (SSSS)
Desmoglein-1 (DSG1) can be inactivated by germline mutations, autoantibody, or bacterial toxins.
Pemphigus foliaceum is an auto-immune blistering disease due to an inactivation of desmoglein-1 by an autoantibody. The relevant antibody in pemphigus foliaceus reacts with desmoglein-1, which is expressed in the uppermost epidermal layers, thus correlating with the characteristic subcorneal plane of blister formation in this variant.
DSG1 can also been inactivated by the exfoliative toxins produced by S. aureus, that are serine proteases that cleave the protein. This can cause the superficial epidermis to split away from the deeper skin, making the patient vulnerable to secondary infections.
Exfoliation can occur at the site of staphylococcal skin infection (bullous impetigo) or can be widespread, when secreted toxin from a localized infection causes disseminated loss of the superficial epidermis (staphylococcal scalded-skin syndrome or SSS).
Staphylococcal scalded skin syndrome (SSSS), also called Ritter disease, is caused by the exfoliative A and B toxins. It is an exfoliative dermatitis that most frequently occurs in children with staphylococcal infections of the nasopharynx or skin.
In staphylococcal scalded skin syndrome, there is a sunburnlike rash that spreads over the entire body and forms fragile bullae that lead to partial or total skin loss.