Impetigo is an infection of the skin that is generally caused by staphylococcus and streptococcus bacteria. This disease is contagious and is spread by close contact and affects more children than adults. Impetigo can be categorized into two kinds with different symptoms respectively:

Non-bullous Impetigo:
This is the more common kind of impetigo that is caused by Strep and Staph bacteria. Non-bullous impetigo results in sores with a yellowish-brown crust which are highly contagious.

Impetigo

Bullous Impetigo:
Only Staph bacteria cause this type of impetigo. Large blisters that are filled with fluid but painless characterize bullous impetigo. Impetigo can also be classified as primary and secondary impetigo. In primary impetigo, the bacteria enter the skin through a cut but the rest of the skin is otherwise healthy. With secondary impetigo, the infection is caused by another underlying condition such as atopic eczema that affects large areas of the skin. 

How is impetigo diagnosed?
Diagnosing impetigo is generally straightforward and based on the clinical appearance. Occasionally, other conditions may look something like impetigo. Infections such as tinea ("ringworm") or scabies (mites) may be confused with impetigo. It is important to note that not every blister means an impetigo infection. At times, other infected and noninfected skin diseases produce blister-like skin inflammation. Such conditions include herpes cold sores, chickenpox, poison ivy, skin allergies, eczema, and insect bites. Secondary infection of these other skin lesions may sometimes occur. Medical evaluation and occasionally culture tests are used to decide whether topical antibacterial creams will suffice or whether oral antibiotics will be necessary.

What is the treatment for impetigo?
Impetigo is not serious and is very treatable. Mild impetigo can be handled by gentle cleansing, removing crusts, and applying the prescription-strength antibiotic ointment mupirocin (Bactroban). Nonprescription topical antibiotic ointments (such as Neosporin) generally are not effective. More severe or widespread impetigo, especially of bullous impetigo, may require oral antibiotic medication. In recent years, more staph germs have developed resistance to standard antibiotics. Bacterial culture tests can help guide the use of proper oral therapy if needed. Antibiotics which can be helpful include penicillin derivatives (such as amoxicillin and clavulanic acid [Augmentin]) and cephalosporins such as cephalexin (Keflex). If clinical suspicion supported by culture results show other bacteria, such as drug-resistant staph (methicillin-resistant Staphylococcus aureus or MRSA), other antibiotics such as clindamycin or trimethoprim-sulfamethoxazole (Bactrim or Septra) may be necessary. Treatment is guided by laboratory results (culture and sensitivity tests).