A – Z of Skin

Information for Skin, Hair and Nail Conditions


The A to Z of Skin information has been developed to help you understand more about common skin conditions and problems, and how these may be treated.

Both common and medical names have been included to help your search, as well as the names of medications and treatments. There are also a number of cosmetic topics which explain the latest treatments for cosmetic concerns related to the skin. Many College dermatologists have contributed to the information on this site.

The process has been overseen by a committee of dermatologists to ensure that the final versions are both accurate and user friendly. Particular thanks go to Dr Pam Brown, Dr Peter Berger, Dr Davin Lim, Dr Michelle Rodrigues, Dr Yin Vun, Conjoint Associate Prof Orli Wargon and Dr Eleni Yiasemides (Chair). The A to Z information is currently under development. Please check back on a regular basis for updates and the addition of new topics.

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  • Naevus fusco-caeruleus zygomaticus

    Naevus fusco-caeruleus zygomaticus also known as hori’s naevus, presents as benign (harmless) blue-grey to gray-brown patchy and spotty pigmentation on the prominence of the cheeks.

  • Naevus of Ota (NOO) and Ito (NOI)

    Naevus of Ota is a pigmented birthmark that is slate-brown or blue/grey in colour. When examined under a microscope, the pigmented naevus cells are found in the deep layer of the skin (dermis).

  • Naevus sebaceous

    Naevus sebaceous is a birthmark usually seen on the scalp or face of newborns and infants. In rare cases it can be present on other areas of the body. Naevus sebaceous can be thought of as being similar to a birthmark but made up of sebaceous cells.

  • Naevus spilus

    Naevus spilus is a type of birthmark that consists of a flat brown background patch containing darker brown spots or tiny bumps.

  • Nails

    Nails are specialised protective plates of hard keratin (protein that helps form the nail plate) that develop from the epidermis (outermost layer of the skin) overlying the small bones at the ends of the fingers and toes.

  • Nappy rash

    Nappy rash is a common, irritant dermatitis occurring in the nappy area, mostly in children under the age of two years. It is not primarily an infection or the result of poor hygiene. There are now fewer cases of severe nappy rash because of the increased use of superabsorbent disposable nappies.

  • Necrobiosis Lipoidica

    Necrobiosis lipoidica is a rare skin condition which typically affects the lower legs. It is characterized by shiny red yellow plaques which usually enlarge and persist for years.

  • Neonatal acne

    Neonatal acne affects babies in the first 3 months of life. About 20% of healthy newborn babies may develop superficial pustules mostly on the face but also on the neck and upper trunk

  • Neonatal and infantile acne

    Neonatal acne affects babies in the first 3 months of life. About 20% of healthy newborn babies may develop superficial pustules mostly on the face but also on the neck and upper trunk.

  • Neonatal cephalic pustulosis

    Neonatal cephalic pustulosis also known as neonatal acne affects babies in the first 3 months of life. About 20% of healthy newborn babies may develop superficial pustules mostly on the face but also on the neck and upper trunk

  • Neonatal lupus erythematosus

    Neonatal lupus is an autoimmune disease. It occurs when an antibody is transferred from the mother to the baby. The antibody can affect the baby’s skin, heart, liver, blood and brain. Neonatal lupus is rare with an incidence of 1 in 20,000 pregnancies.

  • Neurodermatitis

    Neurodermatitis also known as Lichen simplex chronicus, is characterised by thickening of the skin due to chronic rubbing or scratching. Exaggerated skin markings termed “lichenification” are common.

  • Neurotoxins

    Neurotoxins are a group of substances that are used in dermatology to treat hyperhidrosis (excessive sweating). They are also used to reduce wrinkles, most commonly those around the eyes and on the forehead

  • Nevus araneus

    Nevus araneus also known as a Spider naevus is a common harmless vascular lesion seen in up to 10% of the population. They usually appear as single or multiple spots on the face, chest and neck areas. As the name suggests, Spider naevus has a central red spot with tiny blood vessels radiating like spider legs from the centre. Spider naevus can be safely treated with vascular lasers.

  • Nevus flammeus

    Nevus flammeus also known as a port-wine stain, is a pink to red flat patch on the skin which has well-defined edges.  It is a true birthmark present in 3 to 5 per 1000 newborn babies. It is permanent and its area will increase in proportion to general body growth.

  • Non Tuberculous Mycobacteria

    The most common skin infections seen in Australia are caused by members of a subgroup of mycobacteria called Atypical Mycobacteria, commonly found in soil, water and other animals.

  • Norwegian scabies

    Norwegian scabies is a more severe form of scabies. Scabies is a condition that occurs as a result of infestation with a tiny mite (parasite) called Sarcoptes scabei var hominis.

  • Notalgia paraesthetica

    Notalgia paraesthetica is a disorder where an often intense localised itch occurs without a rash on the mid to upper back between the shoulder blades. It is thought to be due to sensory nerve irritation rather than a primary skin condition. It tends to run a chronic course. There is currently no cure but there are treatments that can help control the itch.

  • Nuchal Keloid Acne

    Nuchal Keloid Acne also known as Acne keloidalis nuchae (AKN) is a chronic inflammatory condition that affects hair follicles on the back of the neck. AKN is most commonly seen in men of African-Caribbean background but it is also seen in those of Hispanic, Asian, Middle Eastern and Mediterranean backgrounds. In rare cases, it may also be see in Caucasians. Whilst this condition mostly affects men, women may be affected in some cases (the ratio of  affected men to women is 20:1). The term AKN is misleading because the condition does not form true keloid scars and is not associated with acne.