Differential Diagnoses in Young Patients with Oral Vesicles and Pseudomembranes

Infection Diagnosis

• The American Academy of Pediatrics recommends considering a differential diagnosis that includes viral infections (hand-foot-and-mouth disease, varicella-zoster), bacterial infections (diphtheria, Vincent's angina), and non-infectious causes (Behçet's syndrome, erythema multiforme, drug reactions) in patients with oral vesicles and pseudomembranes 1, 2
• The Centers for Disease Control and Prevention (CDC) notes that primary herpetic gingivostomatitis (VHS-1) typically presents with fever, irritability, painful submandibular lymphadenopathy, and painful superficial ulcers affecting the gums, oral mucosa, and perioral area 1, 3, 2
• The CDC also reports that the characteristic evolution of VHS-1 includes grouped vesicles on an erythematous base that rapidly rupture to form irregular ulcers covered by yellow-gray membranes 2
• The World Health Organization (WHO) states that the duration of VHS-1 is approximately 12 days, with maximum viral titers in the first 24 hours 2
• The CDC recommends considering hand-foot-and-mouth disease (enterovirus) in the differential diagnosis, characterized by a distinctive distribution of lesions on the palms, soles, and perianal region, as well as the oral cavity 1
• The WHO notes that varicella-zoster (primary infection) presents with a generalized vesicular rash in different evolutionary stages, not limited to the oral cavity 4
• The CDC reports that diphtheria is characterized by a distinctive grayish pseudomembrane that bleeds when attempted to be removed, with predominant pharyngeal involvement 1

Non-Infectious Diagnosis

• The European Academy of Dermatology and Venereology recommends considering Behçet's syndrome in the differential diagnosis, characterized by recurrent aphthous ulcers, typically without preceding vesicles 5, 6
• The American Academy of Dermatology notes that erythema multiforme is characterized by target lesions on the skin, with involvement of the lips and oral mucosa 5
• The WHO reports that pemphigus vulgaris is characterized by flaccid blisters that rupture easily, leaving extensive erosions 5

Diagnostic Approach

• The CDC recommends a thorough clinical evaluation, including the distribution of lesions, lymphadenopathy, and severity of symptoms, to guide the diagnostic approach 1, 2
• The WHO notes that laboratory confirmation is essential when the diagnosis is uncertain, using methods such as PCR for VHS DNA, viral culture, or immunofluorescence direct or antigen detection 5, 6, 1
• The CDC recommends considering coinfection, such as VHS and Treponema pallidum, which can occasionally be recovered from the same lesion 5, 6
• The American Academy of Pediatrics recommends indications for laboratory confirmation, including uncertain or atypical clinical presentation, systemic illness, immunocompromised patients, and when the diagnosis impacts treatment decisions [1, 3, 2] [1, 2, 3, 4, 5, 6]