The patient's presentation includes erythematous edematous plaques on the face over existing hypoanaesthetic patches, along with pain. Given that the patient has been on MBMDT (multibacillary multidrug therapy) for leprosy for the past 2 months, this suggests a reaction related to his condition.
The options provided are:
- Cellulitis of face
- Type 1 lepra reaction
- Erythema Nodosum Leprosum (ENL)
- Erysipelas
Let's analyze the possibilities:
- Cellulitis of face: A bacterial infection characterized by red, swollen, and painful skin, which fits the description. The rapid development and pain align with an infectious process.
- Type 1 lepra reaction (Reversal Reaction): Occurs in patients with borderline leprosy experiencing immune response changes. It involves erythema and swelling of existing lesions but is less likely to develop as acutely painful without visible nerve swelling or function loss in this context.
- Erythema Nodosum Leprosum (ENL): Typically presents with painful nodules, fever, and systemic symptoms, not usually localized to hypoanaesthetic patches.
- Erysipelas: A bacterial skin infection with sharply demarcated edges, often associated with fever. However, the absence of systemic symptoms or description of sharply demarcated borders makes this less likely.
Considering the clinical signs and the patient’s recent history of MBMDT for leprosy, the most fitting diagnosis is cellulitis of face due to its symptomatic match with acute, painful, erythematous, and edematous skin changes consistent with a bacterial infection. Prompt medical treatment with antibiotics is necessary to manage this condition effectively.