Not So Familiar Skin Conditions

There are approximately 3000 skin conditions often with long Latin names attached to them. Some of these long Latin names may be misleading and intimidating.

Although many of these conditions are rare, as dermatologists we see these rare conditions quite frequently. With some insight into these not-so-familiar skin conditions, they can be prevented and treated.

Phytophotodermatitis

This is where a plant that contains the chemical Psoralen comes into contact with the skin plus sun exposure. Twenty-four hours later, the person will experience very itchy blisters at the site of contact with the plant. These blisters will eventually break and unfortunately, often heal with marked post-inflammatory hyperpigmentation. In my Dermatology practice I have seen this in three different clinical settings:

1. In the summer months, young children may climb into a fig tree. The exposed parts of the body then come into contact with the sap from the fig tree and twenty-four hours later they develop distinctive itchy blisters on the exposed parts of their body.
2. Hikers who walk in the beautiful mountains of the Western Cape in summer may brush against the Blister Bush (scientific name: Peucedanum galbanum). Again, the characteristic itchy blisters appear, often arranged linearly twenty hours later on the exposed areas that were in contact with the Blister Bush.
3. Weed-eaters (Weed whackers) Dermatitis – this again usually occurs in summer when a person weed-eats their garden and small amounts of a plant come into contact with an exposed part of the body. Again, twenty-four hours later, the person will develop itchy areas where the plant material has come into contact with the body. Again, blisters form often leaving marked post-inflammatory hyperpigmentation.

To prevent the above scenarios from occurring, you should wear proper clothing to protect yourself from coming into contact with the offending plant. It is the longer wavelength UVA from the sun that triggers this phototoxic reaction in the skin. Therefore, another way of preventing this dermatitis from occurring is to use a high-factor, broad-factor spectrum sunscreen prior to your outdoor activity in the summer months, specifically this sunscreen must have good UVA coverage.

Product Recommendations:

• La Roche-Posay Anthelios UVMUNE 400 Invisible Fluid SPF 50+
• La Roche-Posay Cicaplast Balm B5 40ml

Keratolysis Exfoliativa

This is where you get very superficial air-filled blisters usually on the fingers and palms of young active persons. It tends to occur more frequently in people with sweaty palms and soles. These blister breaks leaving a red area with a superficial scale on the edge. It is usually not itchy.

The treatment is to wash your hands with a gentle cleanser and apply a healing balm.

Product Recommendations:

• CeraVe Hydrating Cleanser 236ml
• SBR Repair Cream 30g

Polymorphous Light Eruption

This is a very itchy rash that is more common in temperate climates where there are definite seasons and less sun in the winter. It commonly occurs in the springtime where an area that is normally protected by clothing during the winter comes into contact with the sun. It usually occurs twenty-four to forty-eight hours after sun exposure and has various clinical presentations hence the name ‘polymorphous’. It may be triggered by UVB as well as UVA radiation.

The itch may be quite severe and it often requires a potent prescription topical corticosteroid cream to settle the rash.

Prevention is by using protective hats and clothing and especially using a high-factor broad-spectrum sunscreen on the first exposure to sunlight in the spring

Product Recommendations:

• Heliocare Spray SPF 50
• La Roche-Posay Thermal Spring Water

Erythema Ab Igne (EAI)

As the name suggests, this is quite a common condition that is caused by chronic exposure to heat and thus infrared radiation. This may be from sitting in front of a fire or heater but I commonly see this in my Dermatology practice in patients who apply a hot water bottle to areas like the lower back, and lower abdomen for pain relief. This presents with a chicken-wire-like reddish/brown discolouration of the skin with atrophy. There is a small risk of a squamous cell carcinoma developing at the site of this skin condition.

More recently I have seen a number of patients in my practice who develop EAI on their anterior thighs.  This is a result of resting a laptop on their thighs when they are working. The heat from the battery causes these characteristic skin changes. If you realise that your skin has been exposed to excessive heat from whatever source, then I would recommend a soothing, fragrance-free moisturiser to be applied immediately.

Product Recommendations:

• CeraVe Moisturising Cream 340g
• Bioderma Atoderm Intensive Baume

Unfortunately, once there is the mottled hyper and hypopigmentation there is no real effective treatment available.

Lichen Simplex Chronicus (Scratch Patch)

This tends to be a chronic itchy skin condition where a person gets into a habit of scratching an easily reached spot or patch on the skin eg. side of the neck & side of the calf. The affected area is often repeatedly scratched subconsciously when stressed.

The treatment is to try to break the scratch | itch | scratch cycle. When stressed the person can squeeze a ball or spin a fidget ring instead of scratching the skin.

A prescription of an ultra-potent topical corticosteroid cream in addition to a gentle cleaner & calm soothing skin balm is often recommended.

Product Recommendations:

• Bioderma Atoderm Intensive Foaming Gel 1L
• ISDIN Nutratopic PRO-AMP® Emollient Lotion