The molluscum contagiosum virus' (MCV) symptoms are easily recognized in their most usual form. It should be noted, however, that many people infected with the virus do not exhibit any symptoms. MCV causes solid, raised bumps with a tough, hornlike centre. They are distinct from one another and waxy in appearance and are usually small, though they not infrequently grow to 5mm in diameter. They have a firm, rubbery consistency and often have a dimple at the centre. They are not usually painful. When squeezed these papules (solid, raised spots on the skin) emit a cheesy or curd-like material made up of the husks of skin cells carrying the virus. They may also be accompanied by redness or scaling. As they heal, the papules shrink and leave a pitted surface. About ten percent of people with molluscum lesions (skin abnormalities) develop eczema around them, though this may actually be part of the body's response to the papules and sign that they are clearing up.
They can be grouped in clusters or appear in a linear pattern, particularly where they develop at the site of an injury, such as a scratch. The virus appears to favour moist conditions, so papules are often found in the armpits, groin, or the back of the knee. They may also be found particularly in front of the elbow (where blood is frequently drawn). They rarely ever affect the palms of the hands or the soles of the feet. There are usually less than twenty papules present. For those with weakened immune systems due to HIV/AIDS, Hodgkins Disease, organ transplants, etc., the appearance of papules tend tends to be more numerous, more disfiguring, and more persistent.
The virus is usually diagnosed based on the distinctive appearance of the papules it causes, but examining the contents expressed from the papules can confirm a diagnosis as there are some other skin ailments that can cause similar lesions. The lack of dead tissue and inflammation surrounding most papules, however, helps to set those of molluscum contagiosum apart from those caused by other varieties of poxvirus (the family of viruses to which MCV belongs). Similar symptoms may be caused by several other skin ailments, including genital acne, warts, herpes sores, and pearly penile papules, so patients and health care practitioners should be aware of the differences. Some, like pearly penile papules, are harmless and do not require any treatment. In these cases, treatments intended for molluscum lesions may cause unnecessary pain, expense, scarring, and lightening or darkening of the skin. Treatments for warts caused by the human papilloma virus (HPV) are usually similar to those for molluscum papules and are less of a cause for concern. Genital pimples and herpes, however, require treatments very different than those for molluscum lesions. It is particularly important that warts in the genital areas and herpes sores are treated because the herpes virus remains in the body for life, and HPV persists even when symptoms are not visible (though the virus usually dies after two years), making it necessary to take precautions to minimize transmission.