Staphylococcal bullous impetigo in a neonate

Table 1 Differential diagnosis of Staphylococcal bullous impetigo in neonates

Causes	Characteristic features
Infectious causes
Herpes simplex virus	Grouped vesicles on an erythematous base that rupture to become erosions covered by crusts; may have prodromal symptoms
Varicella zoster virus	Lesions of different stages are present at the same time in a given body area as new crops develop
Streptococcus spp.	Similar lesions with Gram stain showing Gram positive cocci in chains. Further differentiated on the basis of culture characteristics and biochemical tests
Treponema pallidum	Diffuse erythematous lesions containing large number of treponemes. Associated systemic involvement
Staphylococcal scalded skin syndrome	Cutaneous tenderness, positive Nikolsky sign, large areas of desquamation or exfoliation. Infection spreads hematogenously because of absence of protective antitoxin antibodies. Culture of bullae is negative
Cutaneous candidiasis	Generalized skin eruptions at birth, characterized by erythematous macules and papules Candida albicans demonstrated on direct KOH smear, skin biopsy
Listeriosis	Presents with systemic signs and symptoms of sepsis
Pseudomonas skin infection	These may present as localized cutaneous folliculitis or as necrotising infection, ecthyma gangrenosum. Lesions are painful and systemic involvement may be seen. Diagnosis is confirmed by isolation of Pseudomonas aeruginosa from lesions
Noninfectious causes
Bullous erythema multiforme	Usually involves extensor surfaces of extremities
Bullous lupus erythematosus	May be pruritic; tends to favor the upper part of the trunk and proximal upper extremities
Bullous pemphigoid	Vesicles and bullae appear rapidly on widespread pruritic, urticarial plaques
Pemphigus vulgaris	Healing with hyperpigmentation
Stevens-Johnson syndrome	Vesiculo-bullous disease of the skin, mouth, eyes, and genitalia; ulcerative stomatitis with hemorrhagic crusting is most characteristic feature
Toxic epidermal necrolysis	Stevens-Johnson–like mucous membrane disease followed by diffuse generalized detachment of the epidermis
Insect bites	Bullae seen with pruritic papules grouped mainly in exposed parts of body
Thermal burns	History of burn with blistering in second-degree burns
Neonatal pustular psoriasis	Sterile widespread pustules on an erythematous background
Erythema toxicum neonatorum	Benign self-limited eruption occurring in early neonatal period in healthy neonates. Macular erythema, papules, vesicles or pustules
Neonatal acne	Acneform eruptions in newborn often seen on nose and adjacent portions of cheek