Diagnostic Considerations
Clinical differential diagnoses and their key differentiating features are listed below:
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Dermatitis herpetiformis - Vesicular; pruritus more severe; extensor distribution
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Folliculitis - Follicular papules; pustules if lesions intact
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Arthropod reaction - Tendency to cluster; extremities and exposed sites usually involved
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Papular urticaria (prurigo simplex) - Primarily excoriations; unreachable areas tend to be spared
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Miliaria rubra - History of exacerbation with heat; often more nodular lesions
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Papular drug eruption - Papules tend to coalesce into plaques; no sparing of extremities
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Disseminated herpes simplex or herpes zoster - Vesicular; painful; history of immunosuppression
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Scabies - Intractable itching, worse at night; wrists, finger webs, and axillae affected
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Papular pityriasis rosea - Herald patch, less severe or absent pruritus, collarette of scale; seasonal incidence
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Secondary syphilis - Usually scaly, with palmar lesions; pruritus is mild or absent
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Galli-Galli disease [13] - Primarily affects lower extremities, groin, hands (larger body parts)
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Darier disease- Follicular involvement
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Pemphigus foliaceus - Erosions
Differential Diagnoses
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Galli-Galli disease
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A 54-year-old man with a pruritic eruption on the trunk. Notice the slight lichenification and significant erythema from rubbing that is localized to the central part of the torso. Also note the red-brown papules in the abdominal region.
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Close-up view of the abdominal area of a patient with a pruritic eruption on the trunk. Multiple, small, discrete, red-brown papules characteristic of Grover disease are present.
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Histopathology of Darier-type Grover disease. A focus of acantholytic dyskeratosis is present in the epidermis with slight epithelial hyperplasia and hyperkeratosis, a sign of rubbing as a consequence of the pruritic nature of the disease (hematoxylin and eosin, original magnification X40).
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Higher magnification reveals the acantholytic dyskeratosis to better advantage. Note the corps ronds and grains (hematoxylin and eosin, original magnification X400).
