Yes, Manforce 100 mg, which contains Sildenafil Citrate, can potentially cause allergic reactions, although they are rare. Allergic reactions to medications can vary in severity and may include:

Rashes or Hives: You might develop skin rashes or hives as a reaction to the medication.

Swelling: Swelling of the face, lips, tongue, or throat could occur, which can be serious and requires immediate medical attention.

Itching: Itching is another possible allergic reaction.

Difficulty Breathing: In severe cases, an allergic reaction may cause difficulty breathing, which is a medical emergency.

If you experience any signs of an allergic reaction after taking Manforce 100 mg, seek medical help immediately. It's also a good idea to inform your healthcare provider about any known allergies before starting a new medication. They can help you determine the best course of action and consider alternative treatments if needed.