Quiz 3

 

What is Your Diagnosis?


View Figure  
View Figure  		Figs 26A–B  These clinical pictures appeared as being representative of dermatitis herpetiformis in A Clinical Atlas of 101 Common Skin Diseases by A.B. Ackerman, H. Kerl, J. Sanchez et al.113 What is your diagnosis
 

Our Diagnosis

 
Prurigo pigmentosa
 
This young woman has red papules, papulovesicles, and crusted erosions in the lumbosacral region. The region of the scapula is involved, too. The differential diagnosis clinically includes dermatitis herpetiformis, linear IgA dermatosis, and prurigo pigmentosa.
 
Sections of tissue of a biopsy specimen taken from a fully developed lesion in this patient are pictured in Figures 26 C–F. The findings in this subepidermal vesicular dermatitis are those of prurigo pigmentosa and not of dermatitis herpetiformis, for reasons that follow:

View Figure  		Fig. 26C  At low magnification, no collections of neutrophils can be seen in dermal papillae at the side of the subepidermal blister.

View Figure  		Fig. 26D  At higher magnification, lymphocytes and eosinophils are scattered along the dermo-epidermal junction.

View Figure  		Fig. 26E  At still higher magnification, lymphocytes and eosinophils are seen better, and keratocytes at the dermo-epidermal junction show vacuolar alteration.

View Figure  		Fig. 26F  Neutrophils are not prominent in the subepidermal blister or in the subepidermal space to the right of it. The infiltrate around the venules in the upper part of the reticular dermis consists of lymphocytes mainly.

View Figure  		Fig. 26G  Although there is a mixture of inflammatory cells in the upper part of the dermis and in the subepidermal blister, eosinophils, rather than neutrophils, predominate.

View Figure  		Fig. 26H  The eosinophils are more numerous than neutrophils in both the upper part of the dermis and in the subepidermal blister.
 
In sum, on the basis of the clinical features and the histopathologic findings, we belive that this patient has prurigo pigmentosa and not dermatitis herpetiformis. Staining by direct immunofluorescence was not performed.