**7. Anti-p200 pemphigoid**

Anti-p200 pemphigoid is a rare, recently described subepidermal autoimmune blistering disease characterized by autoantibodies against a 200 kDa glycoprotein localized within the lower lamina lucida in the basement membrane zone [68].

The disease presents as tense blisters with urticarial papules and plaque, as in bullous pemphigoid, and develops in the younger population, along with significant acral and cephalic distribution and mucosal involvement. Cases with similar findings with other subepidermal bullous diseases have also been reported. An association with psoriasis has been reported in 28.3% of patients mostly in Asian patients. In addition to the rarity of the disease, its exact incidence is unknown because it is clinically similar to other bullous diseases and unavailable detective technology in most countries.

Histopathological examination reveals subepidermal separation and a moderate to dense inflammatory infiltrate in the upper dermis, usually with a predominance of neutrophils but sometimes with significant numbers of eosinophils. Linear deposits of immunoglobulin (Ig)G and C3 are detected along the dermal-epidermal junction by direct immunofluorescence microscopy of perilesional skin [68]. In indirect immunofluorescence examination of salt-split skin, the serum sample is bound to the dermal side of the skin. Diagnosis of anti-p200 pemphigoid should be confirmed by the detection of antibodies directed against a 200 kDa dermal protein by enzyme immunoassay(ELISA). In addition, autoantibodies against the 200 kDa protein in the dermal extract can also be demonstrated by immunoblot [68].

Since the disease has been described recently, a standard treatment algorithm has not been defined. The disease usually responds well to bullous pemphigoid treatment [68]. As in other bullous diseases, topical corticosteroids are primarily used in the treatment of localized diseases. A combination of systemic corticosteroids and adjuvant immunomodulatory agents is preferred for systemic treatment. Unlike bullous pemphigoid, dapsone is the most preferred adjuvant agent in this disease [69].
