Molluscum contagiosum
Molluscum contagiosum is a viral skin infection that involves the outer layer of skin, producing tiny white bumps. The centre of the bump may have a depression filled with white material. Molluscum is contagious. The bumps can appear anywhere, including the face. Usually it causes no harm.
Viral warts
Warts are caused by a virus (the human papillomavirus) that infects the outer layer of skin. The most common presentation is a raised, rough bump. It commonly occurs on the hands and feet, but may infect other parts of the body. Warts can also be flat; these are known as plane warts and are typically found on the face.
Shingles
Shingles is a painful blistering rash caused by the same virus that causes chickenpox, known as the varicella zoster virus. After a person has had chickenpox, the virus remains dormant in some of the nerves linked to either the spinal cord or nerves of the head and neck region. If the virus becomes active again, it multiplies and moves along the nerve fibres to the area of skin supplied by those nerves; shingles then appears in this area. The first symptom is often a burning pain or tingling sensation, or extreme sensitivity in one area of the skin. This may be present for one to three days before a red rash occurs. Groups of blisters on a red base usually follow. The blisters last for two to three weeks, during which time pus may appear and then crust over and begin to disappear. The pain may last longer. The blisters usually appear on only one side of the body.
Herpes Simplex
Herpes simplex is an infection of the skin with the herpes simplex virus. There are two types of herpes virus, called herpes simplex type 1 and herpes simplex type 2. Herpes infection is caught from another person through contact with the mouth, eyes or genital secretions or through direct contact with an active lesion. Herpes simplex type 1 usually infects the mouth or eye and herpes simplex, while type 2 usually infects the genital area.
After the virus infects the person, whether it shows on the skin or not, it goes to local sensory nerves and lies hidden (dormant) until reactivation (recurrence of the herpes infection). Reactivation can occur after a few weeks or even years, when the virus travels to the skin supplied by the nerve and appears as a blister or rash on the skin. The first symptom is a burning or stinging pain at the affected site, followed by pink bumps and small blisters. The blisters quickly dry and crust over, and the areas usually heal within a few days. The commonest areas to be affected by herpes simplex are the lips (as cold sores), and the genital area (as genital herpes).
Impetigo
Impetigo is a bacterial infection of the skin, commonly caused by Staphylococcus or Streptococcus. Impetigo is more likely to develop in skin with poor barrier function such as eczema. It may also develop in people with poor skin hygiene or from contact with someone with infected skin. Impetigo can appear as painful sores with yellow crusts stuck to the skin. It appears commonly on the face and limbs, but can develop anywhere.
Boil/Furuncle
A boil, or furuncle, is an abscess (infection) of the skin that starts in the deep part of the hair follicle. The infection is usually caused by a bacterium called Staphylococcus aureus. The bacteria causing the boil can occasionally spread from one part of the body to another and from one person to another by skin-to-skin contact and contaminated clothing and towels. Boils are more common in patients with diabetes and those who are overweight. Boils may be single or multiple.
A boil often starts as an itchy or tender spot that grows over a few days into a large firm red lump that can become increasingly painful. Boils often develop around the neck, trunk and on the buttocks. As the lump continues to grow the centre of the abscess eventually softens and becomes filled with pus. The pus may then burst through the surface of the skin, or it may settle gradually without bursting. A healed boil tends to leave a red mark, which slowly fades but can also leave a small scar.
Erysipelas and Cellulitis
Erysipelas is a superficial infection, affecting the upper layers of the skin, while cellulitis affects the deeper tissues. They can overlap, so it is not always possible to make a definite diagnosis between the two. Bacteria (germs) get though a break in the skin. This break can be very small, such as from a scratch, insect bite or injection, or from another skin disease such as athlete’s foot, eczema or a leg ulcer. Erysipelas is usually caused by bacteria called streptococci. Cellulitis is also often caused by streptococci, but many other bacteria may be involved, such as staphylococci.
The affected skin will become sore, swollen, firm, warm, and red, and blisters may form. The nearest lymph glands may also become swollen and tender. There may also be fever and chills. Cellulitis is most common on the lower leg and erysipelas on the legs and face, but any area of skin can be affected.
Candidiasis
Candidiasis is a fungal infection of the skin folds such as the underarms, the inframammary area (in women) and the groin and diaper area in infants. The candida fungus thrives in a warm and moist environment. Signs of infection include red areas of skin with scaling, small red bumps and pustules.
Pityriasis Versicolor
Pityriasis Versicolor is a superficial fungal infection of the skin. It usually affects adults and causes an itchy, scaly rash that appears as white, pink or brown patches on the face, neck, chest, back, shoulders and limbs.
This rash is often aggravated by excessive sweating. It is caused by an increase in number of the Malassezia fungus, a skin commensal. This condition is found most often in warm, moist climates. Most people with this condition are perfectly well and healthy.
The rash clears with treatment – though the pale areas may take a few months to return to their normal colour. Pityriasis versicolor does not leave scars, however often the rash does come back.
Ringworm
Ringworm is a common term for superficial fungal infection of the skin which appears as scaly, red, rounded patches with a tendency to form rings. It is known as tinea corporis when it affects the body, and tinea cruris when it affects the groin. Tinea capitis, or ringworm of the scalp, affects mainly children and can cause hair loss. Ringworm of the feet is also known as tinea pedis and is one of the most common fungal infections of the skin. The skin on the soles and toe webs becomes very scaly and peels. It is itchy and occasionally small blisters may appear. This infection can also affect the toenails.
Scabies
Scabies is an itchy skin condition that can present as red bumps, particularly on the hands, skin folds, genitalia and buttocks. The condition is caused by the scabies mite, which is not visible to the naked eye and can only be seen with the help of a microscope.
This condition is transmitted from human to human and often occurs within families. It is easily transmitted during close contact because people with scabies do not feel itchy or have itchy bumps during the first few weeks of infection.