Brief Answer:
Please confirm that it was mosquito bite only and not any other insect.

Detailed Answer:
Hi.
Thanks for your query, albeit short and specific.
Noted the history of mosquito bite on Monday - swollen and red - huge lump - wants to know what to do.

Please provide me additional information for me to assist you better:
Please post clear and focused photos as it some times gives on-the-spot diagnosis.
Any other symptom like itching, fever or so.
Any past history of similar lesions on mosquito bites or anything else?
Any history of medical problems like diabetes?
Where exactly is the swelling?

I think, the formation of a huge lump with redness is very rare on mosquito bite.
Hence you may need an antihistamine like Cetirizine.
Oral steroids if required for its best possible anti-inflammatory and anti-allergy action.
Antibiotic if there is an evidence of an infection locally.

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