History

A dermatological history should include:

Duration - a naevus that has enlarged and blackened over a few months is much more suspicious of melanoma than a lesion that has changed overnight
Associated symptoms - itching, burning, soreness, pain, weeping, oozing, blisters or odour
Site of onset and details of spread - a generalised eczema in a patient with preceding venous eczema is likely to be a secondary ‘autosensitisation’ eruption
Fluctuation or persistence - occupational contact allergic dermatitis or cases where there is a household contact allergen may improve on holidays
Provoking or aggravating factors - some infective and drug triggers may precede the eruption by several weeks
The response or lack of response to previous treatments - topical steroids may help reduce the itch of tinea but they will not improve the extent of the rash, and in some cases they will make it worse (tinea incognito)
Previous episodes - photodermatoses tend to erupt every spring

Personal history
Family history
- Many patients with psoriasis have a family history. On the other hand if the patient cannot account for one it does not rule psoriasis out as a possible diagnosis
- Some genodermatoses have a specific inheritance pattern such as icthyosis and some bullous disorders
- FAMM syndrome (familial atypical mole and melanoma) - is diagnosed when several family members have large amounts of melanocytic lesions, some of which are atypical, and when there is one or more cases of melanoma in the family. Affected family members are at a much increased risk of melanoma and need to be identified for screening
Atopic eczema is associated with asthma and hay fever

There are many examples in which the past medical history is relevant, for example:
- Diabetes and necrobiosis lipoidica
- Connective tissue disease disorders such as SLE are multi-system disorders

Dermatoses may arise from topical and systemic medications, both prescribed and over the counter products
Anabolic steroids causing acne vulgaris
Homeopathic medication used to treat skin disease - not enough is known about homeopathic products, but one has to bear in mind the following:
- A number of systemic products have been found to cause abnormal liver functions tests, or contain significant levels of steroids
- The manufacture of some Chinese herbal products results in major animal cruelty

Both work and hobbies may result in contact allergic dermatitis
Excess exposure to UVR increases the risk of skin cancer
Alcohol can be relevant is three ways:
- Moderate to high consumption alcohol often aggravates chronic inflammatory dermatoses of the skin such as psoriasis
- Patients with chronic skin conditions may become depressed and turn to alcohol
- Patients who drink alcohol are unable to use drugs such as methotrexate due to the increased risk of liver damage
Smoking - cigarette smoking has a close association with palmoplantar pustulosis. Anti-malarial drugs used to treat conditions such as discoid lupus erythematosus are likely to be less effective in patients who smoke
Sexual behaviour - STI can cause localised conditions affecting the genitalia and oral mucosa. HIV is associated with numerous skin conditions
Travel and infectious disease

Skin disease is frequently associated with psychological problems. Stress in itself often aggravates skin conditions
It is crucial to understand how a patient perceives the severity of their skin condition. For example some patients with severe psoriasis have never consulted a specialist, on the other hand a patient with a small ‘spot’ on their face may be devastated
Psychological problems arising from skin disease - the effects may stop patients going out, working, forming relationships. It can lead to depression and occasionally even suicide
Psychological problems may cause skin disease - dermatitis artefactae, delusions of parasitosis

There are a number of situations where this is relevant such as:
- Psoriasis and psoriatic arthropathy
- Unexplained weight loss - in patients presenting with a generalised pruritus without a rash such weight loss may indicate serious underlying pathology, and warrants thorough investigation