When a mosquito bites, it pierces the skin to feed on blood, injecting saliva that contains proteins. The body’s immune system recognizes these proteins as foreign, initiating a response that typically results in a localized reaction. While most individuals experience minor irritation from mosquito bites, some can develop more pronounced allergic responses.
Normal Mosquito Bite Reactions
A typical mosquito bite manifests as a small, itchy, reddish bump, often called a wheal, that appears within minutes. The swelling and redness usually subside within a few days, though a firmer, darker red bump might develop within 48 hours.
Signs of an Allergic Reaction
Some individuals experience a more severe localized allergic reaction to mosquito bites, often referred to as Skeeter Syndrome. The bite site can develop significant swelling, often measuring larger than 2 centimeters across and sometimes affecting an entire limb.
Accompanying this swelling is intense redness and warmth around the affected area, which can be painful. Blisters or dark spots that resemble bruising may also form at or near the bite. Additionally, individuals might develop hives or a widespread rash extending beyond the immediate bite area.
These allergic reactions are often much more intensely itchy and painful than typical bites, and they can persist for days or even weeks. In some cases, systemic symptoms such as a low-grade fever or swollen lymph nodes in the vicinity of the bite can occur.
Distinguishing Allergic Reactions from Infections
Understanding the differences between an allergic reaction and a bacterial infection is important for proper management. Allergic reactions, like Skeeter Syndrome, typically appear within hours of the bite, with symptoms peaking around 24 hours before gradually subsiding. The swelling, redness, and itching are direct immune responses to the mosquito’s saliva proteins.
Conversely, a secondary bacterial infection often becomes evident a day or two after the bite, and symptoms tend to worsen over time rather than improve. Signs of infection include increasing redness that spreads outwards, sometimes forming red streaks, or the presence of pus or discharge. The affected area may also exhibit increasing pain, warmth, or tenderness, and the skin might appear shiny or stretched.
When to Seek Medical Attention
It is advisable to consult a healthcare professional if a mosquito bite shows signs of infection. These signs include spreading redness, pus or discharge, increasing pain, significant warmth, or the development of fever and chills. Red streaks extending from the bite or swollen lymph nodes also warrant medical evaluation.
Medical attention is also recommended for severe swelling that impairs movement or affects vision, such as around the eye. If symptoms persist or worsen over several days despite home care, professional assessment is important. Although rare, immediate emergency medical attention is necessary if signs of a severe systemic allergic reaction, like difficulty breathing, swelling of the face or throat, dizziness, wheezing, or widespread hives, occur.