Synonyms: St. Anthony's fire; ignis sacer. Clinical Presentation (Fig. 2A):

■ Sharply demarkated erythematous or purpuric patch or plaque, sometimes covered by vesicles and/or bullae

■ Often accompanied by edema, lymphangitis, lymphadenitis, and fever

■ Face and lower extremities involved commonly, usually unilateral

■ Lesion is painful

Histopathology (Figs. 2B and C):

■ Sparse to moderately dense perivascular and interstitial mixed-cell infiltrate of lymphocytes, neutrophils, and few eosinophils

■ Erythrocytes extravasated in number

■ Widely dilated venules and lymphatics

■ Edema of the papillary dermis

■ Spongiosis and ballooning of the epidermis sometimes Clinicopathologic Correlation:

Differential Diagnosis:


■ Beta-hemolytic streptococcus is responsible most commonly, Staphylococcus aureus less commonly.

Clinical Presentation (Fig. 3A):

■ Urticarial papules and plaques

■ Abdomen, buttocks, and thighs especially, often beginning in abdominal striae

■ Lesions usually disappear shortly after term

■ Lesions are itchy

■ Primigravidas late in the third trimester Histopathology (Figs. 3B-D):

■ Superficial perivascular infiltrate of lymphocytes (Fig. 3C)

■ Eosinophils scattered interstitially (Fig. 3D)

■ Focal spongiosis and parakeratosis sometimes

Clinicopathologic Correlation:

Clinical Feature

Pathologic Feature

Papules and plaques

Sparse perivascular and interstitial infiltrates of inflammatory cells and slight edema in the upper part of the dermis


Dilated blood vessels

Subtle scale


Differential Diagnosis:


Insect Bites

Perivascular and interstitial infiltrate

Dense, wedge-shaped infiltrates, perivascular and interstitial

Neutrophils and eosinophils

Lymphocytes and eosinophils

No changes in the epidermis

Spongiosis in the center of the lesion



1. Aronson IK, Bond S, Fiedler VC, Vomvouras S, Gruber D, Ruiz C. Pruritic urticarial papules and plaques of pregnancy: clinical and immunopathologic observations in 57 patients. J Am Acad Dermatol 1998; 39(6):933-939.

2. Callen JP, Hanno R. Pruritic urticarial papules and plaques of pregnancy (PUPPP). A clinicopathologic study. J Am Acad Dermatol 1981; 5:401-405.

Clinical Feature

Pathologic Feature


Dilated vessels

Purpuric color

Extravasated erythrocytes

Vesicles and bullae

Extensive edema of the papillary

Was this article helpful?

0 0

Post a comment