Polymorphic Light Eruption
It presents with erythematous lesions triggered by ultraviolet rays, usually appearing on sun-exposed areas of skin such as the face, neck and décolleté. The skin lesions, accompanied by itching, consist of papules, vesicles or plaques. The plaques are urticarial and eczematous in nature. Phototoxic reactions: erythema usually appears on the face when a person is exposed to the sun after taking drugs that sensitise the skin to sunlight, such as psoralen, tar, tetracycline and thiazide diuretics.
Photocontact Dermatitis
Photocontact dermatitis, which occurs mainly due to the effect of ultraviolet (sun) rays, is divided into two types: photoirritant (phototoxic) and photoallergic contact dermatitis. The face, the V of the upper chest, the backs of the hands and the outer parts of exposed forearms, which are exposed to sunlight, are the areas where lesions are most commonly seen.
Photoirritant Contact Dermatitis
This is an inflammatory skin reaction that develops photochemically in areas of skin exposed to sunlight, especially UVA, and usually occurs in most of those exposed, at the first contact. Immunological mechanisms play no role in its development. For a photoirritant reaction to develop, a substance that shows its irritant effect only in the presence of light of the appropriate wavelength must come into contact with the skin. The clinical picture may resemble a first- or second-degree sunburn.
In addition, lesions occur only in areas of skin that have been exposed to light.
Berloque dermatitis, caused by the effect of psoralens in perfumed substances, and phytophotodermatitis, caused by the effect of furocoumarins in plants, are two common types of photoirritant dermatitis. The main plants causing phytophotodermatitis are fig, celery, carrot, parsley and lemon. The main photoirritant substances are tars, psoralens, furocoumarins, anthraquinone and acridine-derived dyes (such as acriflavine, rivanol and fluorescein) and drugs (sulphonamides, chlorpromazine, tetracycline and quinolone derivatives).
Photoallergic Contact Dermatitis
This is an immunological reaction that develops with allergenic substances and requires light with a wavelength of 280–600 nm. For a photoallergic reaction to occur, the person must have been previously sensitised. In any given case it is difficult to distinguish these two types of reaction from each other. Clinically it resembles allergic contact dermatitis.
The main photocontact allergens are phenothiazines (antipsychotics, insecticides and anthelmintics), sulphonamides, plant allergens, NSAIDs, cosmetic products and sunscreens.
Photo-onycholysis
Photo-onycholysis is a rare phototoxic reaction resulting in separation of the nail plate from the nail bed due to UV rays. The aetiology of photo-onycholysis includes drugs (tetracyclines, fluoroquinolones, non-steroidal anti-inflammatory agents, psoralens, retinoids, zidovudine, quinine, etc.), diseases characterised by photosensitisation such as porphyria, and spontaneous development.
Tetracyclines are among the drugs that most commonly cause photo-onycholysis. In addition, drugs such as psoralens, fluoroquinolones, chloramphenicol, oral contraceptives and chlorpromazine can also cause photo-onycholysis. Photo-onycholysis appears immediately after taking the drug or a few weeks after the drug is stopped. In this case, it was learned that photo-onycholysis appeared in the second week of doxycycline started for the treatment of brucellosis.
Photo-onycholysis is rarely seen in children and usually affects a few fingers. It is notable that the case was a child and that all the fingernails were affected. As toenails are less exposed to sunlight, photo-onycholysis is rarely seen there, whereas it is more often observed in fingernails. In patients with photo-onycholysis, nail discolouration and, rarely, pain are observed. In this case there was discolouration and pain in the fingernails, and the toenails were normal. Although photo-onycholysis is often accompanied by a skin rash, there was no skin rash in this case.
Clinically, nail separation has three subtypes. Type 1 is the most common type, and the separation is distal and half-moon shaped. In type 2 there is a circular notch proximally. In type 3 the lesions are in the centre of the nail plate. The photo-onycholysis in this case was consistent with the rare type 2.
The nail structure behaving like a convex lens and focusing UV rays on the nail bed causes nail damage. In addition, the fact that the nail bed contains less melanin than the skin, and the absence of the stratum granulosum and sebaceous glands, also limit photoprotection. This patient had been exposed to intense and prolonged sunlight because he grazed animals. In addition, due to the geographical conditions of the region (northern hemisphere, 39–41° north latitude and 1140 metres) and the summer season, the sun's rays reached him at a steeper angle. These factors are thought to have played a facilitating role in the development of the condition.
The diagnosis of photo-onycholysis is made by excluding other causes that may lead to onycholysis (dermatological diseases, systemic diseases, products brought into contact with the nail, etc.). Although doxycycline is a frequently used antibiotic, few cases accompanied by photo-onycholysis have been reported. No cause other than the drug was identified in the aetiology of this case.
Treatment includes local measures (keeping the nails short, avoiding trauma, avoiding prolonged contact with water, avoiding products that will damage the nails) and stopping the causative drug.. The infectious diseases specialist stopped the doxycycline treatment and started TMP-SMX instead. Photo-onycholysis is a benign condition and regresses spontaneously 3–6 months after the drug is stopped. When the patient was called back for an outpatient check-up a month later, the pain had subsided and there was partial improvement in the nails. The patient did not attend subsequent follow-ups.
In conclusion, patients started on doxycycline for prophylactic or therapeutic purposes should be informed about its possible side effects. Sun-protective clothing and creams against sun exposure, and for women coloured nail polish, may be recommended.
Photoageing
Ageing is an inevitable and natural process that increases over time. As a person ages, the biological activity of the cells in the body decreases, their regenerative properties slow down, the detoxification mechanism declines and the immune system becomes less effective. Skin ageing can be divided into two groups: chronological ageing and photoageing. The premature ageing changes that ultraviolet (UV) radiation causes in our skin are called "photoageing".
Photoageing describes the process consisting of complex skin changes caused by chronic ultraviolet exposure, particularly in sun-exposed areas of the skin. The photoageing process varies. It varies according to skin type and ethnic differences. The severity of photoageing also varies according to geographical location, lifestyle and occupation. Exposure to ultraviolet light of different intensities, the use of sunscreen, physical protection and the amount of shade protection are also among the factors that determine the severity of photoageing.
The term photoageing first came into use in 1986 and today it is also used interchangeably with the term dermatoheliosis. However, the term dermatoheliosis is more often used to describe the pathological (osis) consequences of the sun (helio).
Toasted Skin Syndrome (Erythema Ab Igne)
Erythema ab igne, or toasted skin syndrome, is a brownish redness, or the resulting net-like discolouration, that occurs as a result of prolonged exposure to high heat, usually without a burn forming.
It usually occurs in people who work with heat sources (for example stokers, bakers, blacksmiths, glassworkers and cooks). It often occurs in women due to sitting in front of a heater and is seen on the legs. It can also occur on the back or abdomen due to the use of hot-water bottles, heat pads or electric blankets. This condition can sometimes also be seen with laptops, computers or car heaters.
It begins with mottling, followed by net-like redness. Different colours ranging from light pink to red and even dark brown are seen on the affected skin. It occurs more often in people with varicose veins and in the elderly.
As treatment, you should stay away from the cause. When you see a dermatologist, creams may be given to reduce the discolouration. However, sometimes this discolouration can be permanent. Because of the risk of developing thermal keratosis (heat-related thickening of the skin) and squamous cell skin cancer on it, you need to be followed up by a dermatologist for a long time.
Cholinergic Urticaria
Cholinergic urticaria, is known as a type of oedematous and itchy disorder of the skin. It is popularly referred to as hives. The shape and size of cholinergic urticaria can vary. It can appear as hundreds of red dots like measles, or as large spots several centimetres in diameter. Cholinergic urticaria is generally seen around the mouth, around the eyes, on the hands, feet and around the genital area. Under normal circumstances, when treated promptly it is possible to get rid of this condition within a few days. However, if the symptoms keep coming back, it is defined as a chronic condition.
How Does Cholinergic Urticaria Develop?
In cholinergic urticaria, active structures called mast cells, when they become active in tissues of the body – especially beneath the skin – secrete a chemical called histamine, which causes the capillaries where they are located to dilate. As a result of this dilation, redness and swelling occur in the skin. Unlike fluid-filled blisters, these bumps are firm and more like swellings. If this condition is not treated early, mast cells can also affect deeper layers of the skin, leading to more serious consequences.
Cholinergic urticaria can also arise due to foods or medicines taken into the body. Substances in both foods and medicines can produce allergic effects in some immune systems after they enter the body. Together with this allergic effect, the mast cells in the body can be activated. This in turn brings about cholinergic urticaria.
Corns and Calluses
Corns are a skin condition characterised by thickening of the skin. They are usually painful. Sometimes they may peel. Sometimes they can appear as painless hardening.
What Causes Corns?
Friction and pressure are usually the cause of corns. The skin tries to protect itself against repeated trauma by blistering. As a result, the surface cells of the skin increase, thickening the skin.
While corns are most often seen on the hands and feet, they can rarely be seen in other areas. These areas are:
- The palms of people who use tools such as rackets and hammers
- Over the joints of the hand
- The sides of the feet due to tight shoes
- The soles of the feet in people who walk barefoot
- Thickening of the soles and palms is known as palmoplantar keratoderma. This condition can also be genetic.
To heal painful cracks:
- Apply ointments, especially those containing petroleum jelly, and cover the area.
- If there is an infection, antibiotic creams should be used.
- If these measures do not help, a dermatologist should be consulted.
Sometimes, if there is a protruding bone beneath the corn, a surgical procedure by an orthopaedic surgeon is required.
Neurotic Excoriation
In patients with neurotic excoriation, the lesions are created by the patient picking or scratching their own skin. The patient has an irresistible urge to pick their skin.
The patient group usually consists of people who are oversensitive, lacking in self-confidence, afraid of making mistakes, sensitive to negative criticism, shy, self-blaming, rigid and perfectionist. Feelings of anger and aggression are excessively suppressed, and these suppressed feelings sometimes emerge as bouts of anger and outbursts, and sometimes take the form of destruction directed at their own skin. A history of rejecting and punishing parents is also common in this group.
In neurotic excoriation, the lesions are located in areas that the patient's hands, especially the right hand, can reach. The face, the extensor surfaces of the arms, the neck, shoulders, backs of the legs, middle of the back and buttocks are the most common areas.
There may or may not be itching in these areas. Sometimes acne, folliculitis (inflammation of the hair follicles), keratin plugs or insect bites in patients can provide an excuse for scratching and picking. Patients can enlarge a small lesion to the point where it cannot be recognised by a dermatologist. Neurotic excoriation on a background of acne is called acne excoriée. Another special form is the creation of cheilitis (eczema of the lips) by constantly biting and picking the lips. Disease activity usually increases at night and when the patient is idle. Some patients are unaware that they are causing it, while others do it for pleasure. Patients do not deny that they create the lesions themselves and accept it, but they claim that their picking is unavoidable and necessary. They usually come to the doctor 5–8 years after onset.
When the patient presents to a dermatologist, small crusted lesions caused by scratching and picking are usually seen. The severity of the disease parallels the severity of the psychological problem, and lesions of different ages may be present together. Although lesions are mostly smaller than 1 cm, they can rarely be 1–2 cm. Most lesions are angular and unnatural in appearance. Where lesions are deep, scars with a brown rim and a pale centre form.
Diagnosis can sometimes be difficult. It can be confused with any itchy disease. The diseases with which it is most commonly confused are dermatitis artefacta and delusions of parasitosis. In dermatitis artefacta, the lesions are usually much larger and the patient does not admit to creating the lesions. In delusions of parasitosis, the history is typical, and the patient says that something is moving under their skin and that they are trying to remove or clean it out.
Patients often do not want to see a psychiatrist, and, as in dermatitis artefacta, the dermatologist may need to arrange the treatment. Once good trust has been established between the patient and the doctor, an attempt should be made to refer the patient to a psychiatrist.
When the disease starts in childhood, recovery is easier. The child's maturation and family support make recovery easier. In adults, those with a short duration respond better. When the disease is not treated, it worsens in parallel with periods of stress, becomes chronic and continues indefinitely.
In psychocutaneous dermatoses, the physician's approach to patients is very important. The patient should be provided with an environment in which they can talk comfortably and should be approached with patience and kindness. The physician touching the patient during the examination puts the person with a skin disease at ease. In these patients, who have intense feelings of guilt and exclusion, touch makes them feel trusted and that they are not found repulsive or excluded. In addition, the physician should be both a good listener and a good observer.
As in neurotic excoriation and dermatitis artefacta, other psychocutaneous dermatoses also require effort, skill and intuition far beyond theoretical knowledge, both in making the diagnosis and in the stages of treatment. Achieving success in such diseases truly requires the use of the art of medicine. Despite all this, however, the existence of a group resistant to treatment must also be borne in mind.
Dermatitis Artefacta
The term dermatitis artefacta is used to describe a distinct entity studied under the heading of psychocutaneous dermatoses. It is created consciously or unconsciously by the patient. It is a rare factitious disorder with various morphological features. As many dermatoses it can mimic and other psychocutaneous diseases enter into its differential diagnosis, a dermatological and psychiatric approach is important.