Clinical and laboratory findings of pigmented purpuric dermatoses

Pigmented purpuric dermatoses (PPD) are chronic, recurrent group of disorders characterized by petechial and pigmentary macules usually localized on the lower limbs. Its etiopathogenesis is unknown. There are very few clinical and etiological studies on PPD in the literature.

We aim to examine the etiopathogenetic factors of PPD retrospectively.

Demographic characteristics, history of co-morbid disorders and drug usage, hepatitis markers, levels of serum lipids, findings of Doppler ultrasonography in lower extremities, and patch test results of the 24 patients of PPD were examined retrospectively. The patch test results, history of drug use, and co-morbid disorders of the patients were compared with those of the control groups.

The male-to-female ratio was 1 : 2, and 83.3% of the patients had Schamberg disease. Seventeen patients had co-morbid disorders and 16 used various drugs, but there was no statistically significant difference between the controls and patients. One patient was positive for hepatitis B surface antigen and 1, for anti-hepatitis C virus antibody. Nine had elevated total cholesterol levels, and 5 had elevated triglyceride levels. Further, 30% of them were positive for at least 1 allergen, while 16% of the control subjects were positive for at least 1 allergen, but statistically significant difference was not found between the 2 groups. Variable degrees of venous insufficiency were detected in 75% of the patients on Doppler ultrasonography of the lower extremities.

Venous insufficiency and hypercholesterolemia might be the basic predisposing factors for PPD. Further studies are needed to show if diabetes mellitus and hypertension may cause perivascular inflammation in PPD.