Pigmented purpuric dermatoses (PPD) 

 

PPD are distinguished by their clinical characteristics, having identical dermatopathologic findings, and Include:

 

·       Schamberg disease, also known as progressive pigmented purpuric dermatosis or progressive pigmentary purpura.

 

·       Majocchi disease, also known as purpura annularis telangiectodes. 

 

·       Gougerot-Blum disease, also known as pigmented purpuric lichenoid dermatitis or purpura pigmentosa chronica.

 

·       Lichen aureus, also known as lichen purpuricus.

 

Salient features

 

·       Clustered petechial hemorrhage

 

·       Often a background of yellow–brown discoloration due to hemosiderin deposition

 

·       The location and pattern depends on the particular variant

 

Introduction

 

Pigmented purpuric eruptions represent a group of diseases characterized by petechial hemorrhage thought to be secondary to capillaritis. PPD are significant only if they are a cosmetic concern to the patient. These diseases have no systemic findings, but they occasionally lead to a patient evaluation to exclude thrombocytopenia or vasculitis because of the purpuric (usually petechial) nature of the lesions and clinical misdiagnosis, especially of the rarer forms.

 

Etiology

 

Exact etiology is unknown. Primary process believed to be cell-mediated immune injury with subsequent vascular damage and erythrocyte extravasation. Other etiologic factors: Pressure, trauma, and drugs (acetaminophen, ampicillin-carbromal, diuretics, meprobamate, nonsteroidal anti-inflammatory drugs, and zomepirac sodium).

 

Pathogenesis

 

These diseases all result from minimal inflammation and hemorrhage of superficial papillary dermal vessels, usually capillaries. The reason for the inflammation is unknown.

 

Clinical features

 

Age/Sex: Peak frequency in middle-aged to older men. Can occur in children.

Morphology: Yellow–brown patches with an oval to irregular outline indicating older hemorrhages and hemosiderin deposition. Recent pinpoint petechiae within patches – likened to “cayenne pepper”. It appears in successive crops

Location: Favors lower legs but can also involve thighs, buttocks, trunk and arms.

 

Onset and Duration: Insidious, slow to evolve except drug-induced variant, which may develop rapidly and be more generalized in distribution. The disease persists for months to years. Most drug-induced purpuras resolve more quickly after discontinuation of the drug. Usually asymptomatic but may be mildly pruritic.

 

Pathology

 

Histopathologic features include red cell extravasation, endothelial cell swelling, a perivascular lymphocytic infiltrate, and hemosiderin-containing macrophages.

 

Treatment

 

Topical low-and middle-potency glucocorticoid preparations may inhibit new purpuric lesions and reduces pruritus. For more extensive disease PUVA and narrowband UVB may be effective.  Successful therapy with ascorbic acid (500 mg twice daily) plus rutoside (50 mg twice daily) has also been reported. Supportive stockings are required in all forms.