Urticaria Pigmentosa

Mastocytosis is characterised by the abnormal growth and accumulation of increased numbers of mast cells in one or more organs. In children, mastocytosis is often cutaneous, and the most common clinical form of cutaneous mastocytosis is urticaria pigmentosa. Urticaria pigmentosa is generally a benign disease. It often begins in the first two years of life, and in most cases remission occurs at puberty. Progression to systemic mastocytosis with extracutaneous organ involvement is uncommon. Patients experience symptoms mediated by mast cell mediators, such as itching, urticaria and flushing. Flare-ups of the lesions are induced by temperature changes, anxiety, physical stimuli, medication and exercise. Symptoms respond to topical and systemic anti-mediator treatments, including antihistamines and sodium cromoglicate. Diagnosis is based on clinical and histopathological findings.

Darier's Disease (Keratosis Follicularis)

Darier's disease is a rare disease which, although it shows autosomal dominant inheritance, is sometimes also seen sporadically.
Its characteristic feature is firm brown papules seen on the central trunk, shoulders, face and other areas. These papules can easily become irritated and/or infected, becoming exudative and crusted. Other features include small pits on the palms and nail dystrophy in the form of a notch at the free edge of the nail where a longitudinal ridge begins.
Similar to the acantholysis seen in pemphigus, there is separation between keratinocytes above the basal layer. Suprabasal clefts are the result of premature keratinisation. As a result of faulty keratinisation, eosinophilic bodies (corps ronds) and small dense basophilic bodies (grains) are seen in the epidermis.
Topical treatment with mild keratolytics such as salicylic acid (2%) or tretinoin (0.025–0.05%) may help. Oral retinoids are other agents that are often considered.

Dermographism

Dermographism is a condition accompanied by itching, with linear raised weals that appear in scratched areas and disappear after a short time. It is a type of urticaria, i.e. hives.
It is seen in 5% of the population. It usually appears suddenly after psychological stress and can continue for many years.
Itching first starts on any part of the person's body; when the person scratches these areas, raised weals form along the lines of the nail marks, the itching gradually spreads and widespread redness develops. It can occur on any area such as the face, neck, arms and legs. It can be triggered by a hot bath, rubbing oneself dry vigorously with a towel, changing clothes or any situation that may cause friction. The itching and weals usually subside within an hour.
In some people, food and drug allergies, house dust and pet allergies, intestinal parasites, thyroid diseases and the presence of Helicobacter pylori bacteria in the stomach can also cause dermographism. Bouts of itching that come in attacks, followed by weals, can cause distress, particularly in social settings.
Treatment uses antihistamines or leukotriene antagonists. Psychological sedatives may also be added. These medicines are used for at least 3 months and are then stopped by gradually reducing the dose over a similarly long period of about 3 months.
Meanwhile, the patient is advised not to eat pickles, hot or spicy foods and nuts. Any medicines that may trigger itching are stopped. Since all medicines, including aspirin, painkillers, blood pressure medicines, birth control pills, herbal supplements and vitamin pills, can be triggers, the patient should inform the dermatologist following them about this.

Solitary Mastocytoma

The mastocytoses are a rare group of diseases resulting from idiopathic proliferation of mast cells in various tissues and/or organs. The skin is the most frequently involved organ, and the disease can cause a variety of clinical appearances. Diagnosis is mostly made in dermatology outpatient clinics. Although usually seen in children, it can also occur in adults. In children there is no systemic involvement and it often resolves spontaneously, but in adult patients there is no tendency to resolve spontaneously and the risk of systemic involvement increases. Urticaria pigmentosa is the relatively more common type of cutaneous mastocytosis; while it presents with maculopapular and/or nodular lesions, solitary mastocytoma may occur as a single lesion or a few lesions, generally larger than those seen in urticaria pigmentosa. Diffuse cutaneous mastocytosis is the form of cutaneous mastocytosis characterised by diffuse, doughy thickening of the skin.

In systemic mastocytosis, usually seen in adults, there is involvement of the bone marrow or other organs outside the skin. Skin lesions may also be present. In all types, in addition to symptoms related to the organ involved, there may also be systemic symptoms caused by the release of biologically active mediators found in the granules of mast cells. Diagnosis is mainly made by skin biopsy. Detailed systemic and laboratory investigations are not required in all patients, but are carried out in those at risk of systemic involvement. Children with systemic symptoms should be followed up by a dermatologist and a paediatrician, and all adult patients by a dermatologist and a haematologist. Treatment of mastocytosis varies according to the type of disease, the severity of subjective complaints and the presence of systemic involvement. In general, there is no treatment that eliminates mast cell infiltration. Teaching the patient about the situations that trigger systemic symptoms is an important preventive measure. Treatments targeting the acute and chronic mediators released from mast cells can also provide symptomatic relief.