Differential Diagnosis for a 16-year-old Female with Sore Throat, Lymphadenopathy, and Oral Mucocutaneous Lesions
Single Most Likely Diagnosis
- Infectious Mononucleosis (Mono): Although the negative strep test reduces the likelihood of streptococcal pharyngitis, the presence of sore throat, lymphadenopathy, and oral mucocutaneous lesions without fever could still suggest infectious mononucleosis, especially given the patient's age and the fact that not all cases present with fever.
Other Likely Diagnoses
- Streptococcal Pharyngitis (despite negative step test): It's possible the test was a false negative, or the infection could be in its early stages. The presence of sore throat and lymphadenopathy supports this diagnosis.
- Viral Pharyngitis: Other viruses like adenovirus, herpes simplex virus, or enterovirus could cause similar symptoms, including the oral mucocutaneous lesions.
- Aphthous Ulcers: Although typically not associated with systemic symptoms like lymphadenopathy, severe cases could present with similar oral lesions.
Do Not Miss Diagnoses
- Lemierre's Syndrome: A rare but potentially life-threatening condition characterized by sore throat, followed by neck pain and swelling, due to a bacterial infection (usually Fusobacterium necrophorum) that can lead to sepsis and jugular vein thrombosis. The absence of fever does not rule out this diagnosis.
- HIV Infection: Acute HIV infection can present with sore throat, lymphadenopathy, and oral ulcers. Given the potential long-term implications, this diagnosis should not be missed.
- Tuberculosis (TB): Although less common in this demographic without specific risk factors, TB can cause chronic sore throat, lymphadenopathy, and oral lesions. The lack of fever does not exclude this diagnosis.
Rare Diagnoses
- Behçet's Disease: A rare condition characterized by recurrent oral ulcers, genital ulcers, and uveitis. It could be considered given the oral mucocutaneous lesions, though other symptoms like genital ulcers or eye involvement would support this diagnosis more strongly.
- Pemphigus Vulgaris: An autoimmune disease causing blistering of the skin and mucous membranes, which could present with oral lesions. However, the presence of lymphadenopathy and sore throat is less typical for this condition.
- Autoimmune Lymphoproliferative Syndrome (ALPS): A rare genetic disorder that affects the immune system, leading to lymphadenopathy and could potentially cause a variety of symptoms including sore throat and oral lesions, though it's more commonly associated with splenomegaly and cytopenias.