Impetigo is a bacterial infection of the skin caused by Streptococcus pyogenes or Staphylococcus aureus. It is frequently seen in school children. This child developed weeping sores and crusting around his mouth. A swab was taken and group A beta-haemolytic streptococcus was cultured. Oral penicillin was prescribed and the mother was advised to apply a cloth, soaked in a mixture of water and vinegar, to the weeping area. Localised areas may be treated with a topical antiseptic or antibiotic ointment such as fusidic acid.
Erysipelas is nearly always caused by the group A beta-haemolytic streptococcus. It presents with a high fever and a rapidly spreading inflammation. It commonly affects the limbs or face. Infection may settle in sores or broken skin, as in this man who had scratched around his hairline. The treatment of choice is penicillin for at least 10-14 days. An episode of erysipelas may lead to lymphatic damage which may lead to recurrences. For repeated attacks, low doses of antibiotics may be recommended on a long-term basis.
Infected surgical wound
This man had undergone a straightforward right inguinal hernia repair. A week later he developed fever and swelling and inflammation around the scar. Culture of a swab taken confirmed the presence of group A streptococcus. The infection quickly responded to oral penicillin and the wound healed.
The risk of developing a wound infection after surgery is greatest after stomach or oesophagus surgery for cancer or bile reflux, intestinal or colorectal surgery and pelvic operations. Prophylactic antibiotics prior to surgery reduces risk of infection.
Peritonsillar abscess (Quinsy)
This young man was complaining of sore throat, difficulty swallowing and problems speaking. On examination he had a high fever, enlarged, tender tonsillar and cervical glands and the left tonsil was swollen and covered in a purulent exudate. A throat swab confirmed group A beta-haemolytic streptococcus. Treatment involves analgesics and antibiotics - IV in severe cases. If the problem fails to respond to antibiotics, the abscess may need to be drained. Complications include pneumonia, pleural effusion, pericarditis, or airway obstruction.
Puerperal mastitis refers to inflammation of the breast resulting from blockage of the milk ducts. This is engorgement and is not necessarily associated with infection. Symptoms include pain, inflammation and swelling. If infection occurs the patient may become ill with a fever. Infection is more likely to occur where the nipples are cracked. The causative organism is commonly Staph aureus or streptococcus.
For infection, penicillin is required for up to 14 days. Breast feeding may continue as there is no risk to the child and the breast benefits from frequent emptying.
Scarlet fever is caused by group A beta-haemolytic streptococcus. The rash is due to a reaction to a toxin produced by the bacteria. In most cases the patient will complain of a sore throat but sometimes the infection originates elsewhere, such as an infected wound. The patient developed an erythematous rash, circumoral pallor, swollen, red 'strawberry tongue', fever and vomiting within 12-48 hours. A 10-day-course of penicillin or erythromycin is required. The rash gradually resolves and desquamation of the skin tends to follow.
- Dr Watkins is a retired GP in Hampshire