The approach to diagnosing CGPD is controversial. Certain dermatologists suggest that ruling out infectious and allergic causes of similar skin eruptions and a skin biopsy demonstrating features consistent with CGPD is adequate for diagnosis. In contrast, other dermatologists advocate for performing a complete history and physical examination and obtaining laboratories and appropriate imaging to rule out cutaneous sarcoidosis. On microscopy, non-tuberculous granulomas with surrounding lymphocytes clustered around hair follicles may be seen; additionally, infiltrates of epithelioid macrophages, lymphocytes, and giant cells may also be seen. Several conditions exhibit skin findings similar to those of CGPD. These conditions include perioral dermatitis, acne vulgaris,<unk>  rosacea, contact dermatitis, folliculitis, atopic dermatitis, cheilitis, medication-induced acneiform eruptions, lupus miliaris disseminatus faciei, benign cephalic histiocytosis, granulosis rubra nasi, xanthomas, zinc deficiency, glucagonoma, cutaneous sarcoidosis, and scabies.
Childhood granulomatous periorificial dermatitis
Chondrodermatitis nodularis chronica helicis
Nutritional deficiency eczema
Acrodermatitis chronica atrophicans
Vulvar childhood pemphigoid
Keratosis follicularis spinulosa decalvans
African blackwood dermatitis
Rodent mite dermatitis