Differential Diagnosis
- Single most likely diagnosis
- Pityriasis rosea: The patient's symptoms, including a single oval patch on the abdomen that progressed to a branching pattern on the trunk, are consistent with pityriasis rosea. The recent upper respiratory infection with fever and chills also supports this diagnosis, as pityriasis rosea is often preceded by a viral infection.
- Other Likely diagnoses
- Tinea corporis: The patient's rash could be a fungal infection, which would need to be treated with antifungal medications.
- Lichen planus: Although less likely, lichen planus could present with a similar rash, and the patient's recent upper respiratory infection could be a trigger.
- Psoriasis: The patient's rash could be an early sign of psoriasis, which would require further evaluation and treatment.
- Do Not Miss
- Secondary syphilis: The patient's rash could be a sign of secondary syphilis, which would require immediate treatment with antibiotics to prevent long-term complications.
- Lyme disease: Although less likely, the patient's rash could be a sign of Lyme disease, which would require prompt treatment with antibiotics.
- Rare diagnoses
- Pityriasis lichenoides: A rare skin condition that could present with a similar rash, but would require further evaluation and treatment.
- Guttate psoriasis: A rare form of psoriasis that could present with a similar rash, but would require further evaluation and treatment.
Treatment for Lichen Planus
The correct answer is: D. Topical corticosteroids. Topical corticosteroids are often used to treat lichen planus, as they can help reduce inflammation and alleviate symptoms. Systemic glucocorticoids (A) may be used in severe cases, but are not typically the first line of treatment. Cold compresses (B) and oral antihistamines (C) may be used to relieve symptoms, but are not the primary treatment for lichen planus.