Parapsoriasis is several chronic non–contagious dermatoses of unclear etiology and genesis with pseudopsoriatic surface rashes on the skin. The main types of parapsoriasis: teardrop-shaped, lichenoid, plaque. Gaberman’s acute parapsoriasis-the Fly – is singled out separately. Polymorphism of primary elements prevails in the clinic without a significant violation of the general condition of the patient. Diagnosis is based on the analysis of clinical manifestations and histology data. The main thing in the treatment of parapsoriasis is the rehabilitation of foci of chronic infection and the treatment of concomitant somatic pathology.
Parapsoriasis (Broca’s disease) is a non–contagious pathology of the skin with little-studied causes and mechanism of development. The eponymous name of the disease is associated with the name of the French dermatologist L. Brock, who described the plaque form of dermatosis and in 1902 combined it with other well-known parapsoriasis. Parapsoriasis includes at least three dermatoses with signs of independent nosologies: red lichen planus, pink lichen and “dry” eczema. All of them clinically resemble widespread psoriasis, but are deprived of its classic triad: the effect of a stearin stain when trying to scrape off scales, varnished terminal film, spot bleeding by the type of dew drops. Until the end of the twentieth century, parapsoriasis was a rare pathology. Today, due to the deterioration of the environmental situation, uncontrolled medication intake, high allergization of the population, the incidence of parapsoriasis is steadily increasing.
The causes of parapsoriasis, the mechanism of its development are under study. There are several theories, the main of which are infectious and immune.
The infectious theory is based on the fact that parapsoriasis is essentially a superficial vasculitis with increased permeability of the capillary walls for bacteria and viruses, in response to the toxins of which the skin reacts with parapsoriatic rashes. This is also evidenced by the fact that parapsoriasis occurs, as a rule, either against the background of infections (sore throat, flu, tonsillitis, pneumonia, measles, chickenpox, mumps, etc.), or immediately after them. However, these arguments are not enough to consider parapsoriasis an infectious pathology, since the same pattern is observed in non-infectious toxicoses, allergies, collagenoses. Moreover, no pathogen capable of causing an infectious disease has been isolated from the blood of patients with parapsoriasis, which unequivocally confirms its non-contagiousness.
In the immune theory, we are talking about an autoimmune reaction from the skin to antigens of various nature, which, once in the human body, reduce general and local immunity, participate in the destruction of DNA and cellular T-lymphocytes. By disrupting the immune balance, they provoke the onset of the disease. The more antigens enter the body, the more powerful and widespread the response. This is how parapsoriasis occurs against the background of foci of chronic infection of the gastrointestinal tract, kidneys, joints or in response to excess ultraviolet light, hypothermia, poor ecology.
Parapsoriasis refers to diseases, manifestations, diagnosis, treatment of which are closely related to a certain clinical form. In dermatology, there are:
- Teardrop-shaped parapsoriasis is a form of dermatosis, the distinctive morphological elements of which are nodules or papules of rounded or hemispherical shape, resembling drops.
- Plaque parapsoriasis – characterized by the presence of scaly rashes – plaques. Depending on the size of the plaques, there are large-plaque (inflammatory and poikilodermic, or atrophic) and small-plaque parapsoriasis.
- Lichenoid parapsoriasis is a form of the disease, the primary element of which is a flat, shiny nodule of skin color, the size of a grain, not rising above its surface, sometimes with an umbilical depression in the center.
- Gaberman-Fly parapsoriasis is an acute dermatosis, a distinctive feature of which can be considered a true and false polymorphism of rashes, as well as a sharp deterioration in the general well-being of the patient at the time of debut.
Teardrop – shaped parapsoriasis
Teardrop-shaped parapsoriasis, or psoriasiform nodular dermatitis, is diagnosed most often. It can have an acute, subacute or chronic course. Dermatosis is out of season, with a recurrent character, has no gender component. The peak incidence occurs at 20-30 years, exacerbations usually occur in spring and autumn. It occurs against the background of severe infections or after them, but it can make its debut in the first trimester of pregnancy, against the background of hyperinsolation, and also without any apparent reasons. The primary element of the rash is a nodule the size of a lentil of any shade of pink or a flat papule the size of a pinhead covered with scales.
The acute form occurs suddenly, with the phenomena of prodrome. Characterized by polymorphism of the rash, the absence of a typical localization, mucosal lesion. The predominance of one or another element in the clinical picture indicates the degree of severity of the process: the appearance of purpura with a hemorrhagic component indicates the onset of the disease, vesicles state the proximity of remission, atrophic elements sum up the parapsoriatic attack. During remission, small scars or pigmentation may remain at the site of the rash.
Subacute teardrop-shaped parapsoriasis occurs without subjective sensations, but with a more pronounced hemorrhagic component. It is localized mainly on the lower and upper extremities. Hyper- or depigmentation remains at the site of the rash. Chronic forms have been around for years. Their distinctive feature is a specific triad of symptoms: false polymorphism (the same elements are at different stages of development), a symptom of a wafer (an attempt to remove scales from the surface of a papule or nodule leads to its complete removal and exposure of the bleeding surface), the presence of a “colloidal film” during resorption of the primary element. There is an almost complete absence of rashes on the mucous membranes, as well as a marked improvement in summer.
Plaque parapsoriasis is a classic Broca’s disease, chronic mottled lichen, dermatosis without subjective sensations, clinically resembling psoriasis or pink lichen. The disease is more common in men aged 30 to 50 years. The period of exacerbation is winter, remission is summer. Diseases of the gastrointestinal tract and genitourinary system are considered to be the provoking moment in the development of dermatosis. Sometimes it is enough to sanitize them so that there is an improvement or a long “light period”.
The primary element is a spot or infiltrated rounded plaque of pale pink color with a yellowish-brown tinge. Its size ranges from 2 to 10 cm, it does not protrude above the skin level, is covered with bran-like scales or a corrugated film resembling tissue paper. The rashes are located on the trunk – parallel to the ribs, on the legs and arms, have no tendency to merge and spread. There is no spot hemorrhage during scraping. The skin of the scalp, palms and soles are practically not affected.
Small plaque parapsoriasis is localized on the lateral surfaces of the trunk, plaques in diameter reach a maximum of 2-3 cm, sometimes look like stripes of different lengths. Plaques do not itch, but they always peel off. Large-plaque parapsoriasis has fundamentally different sizes of plaques (up to 10 cm), the patient begins to worry about itching. With the inflammatory variant, hyperemia and slight soreness appear around the plaques, and with poikilodermic, atrophy in the center of the plaque becomes the main sign. In addition, telangiectasia, depigmentation, mesh hyperpigmentation, follicular keratosis and purpura may be present on the skin simultaneously with plaques. It is this option that, according to scientists, can be reborn into a fungal mycosis, skin lymphoma.
Lichenoid parapsoriasis is extremely rare. Has no gender division, actively manifests itself at the age of 20-40 years. A distinctive feature is the localization of primary elements – cone–shaped oval papules of all shades of red – in the eye area, and not only on the trunk and limbs.
The acute varioliform (smallpox-like) parapsoriasis of Gaberman-Fly stands apart. The disease has no age and gender differences. Some consider it a kind of lichenoid parapsoriasis, others – a variant of teardrop–shaped parapsoriasis, others – one of the forms of independent allergic vasculitis. Distinctive features are: acute onset with obligatory prodromal syndrome (subfebrility, weakness, enlargement of peripheral lymph nodes), polymorphism of the rash, rapid generalization of the process throughout the skin, up to the scalp and soles. The primary elements are symmetrical and have no tendency to merge. The mucous membranes of the mouth, nose, and genitals are involved in the process. If complete regression does not occur within 6 months, parapsoriasis acquires a chronic course. Small atrophic scars remain at the site of the rash.
Diagnosis and treatment
Parapsoriasis is very difficult to diagnose because it has no independent clinical signs. Currently, there are no special laboratory studies for its accurate diagnosis. Taking into account the polymorphism of rashes, the only objective way to confirm the disease is histology, but it also does not give 100% results, so diagnosis must be carried out by a dermatologist. Differential diagnosis is carried out primarily with psoriasis, the classic characteristic of which is the diagnostic triad: the phenomenon of stearin stain, terminal film and drip bleeding, absent in parapsoriasis.
From pink lichen (Vidal’s lichen), parapsoriasis can be distinguished by color and peeling. In lichen Vidal, it is bright pink, peeling is insignificant. Finally, parapsoriasis is often differentiated with papular syphilis. In this case, in addition to syphilitic papules of copper-red color with their palpable infiltration, which even visually differ from rashes of pale pink parapsoriasis, serological reactions to lues (RPR test) help.
Taking into account the result obtained, complex treatment is prescribed. Since there is no etiotropic therapy, they sanitize foci of chronic infection, strengthen the immune system, conduct sessions of UVI and PUVA therapy, spa treatment. In the treatment of teardrop parpsoriasis, antihistamines are used to relieve itching (clemastine) in combination with angioprotectors (troxerutin), calcium preparations. Complex vitamin therapy (B, C, PP, A, E) is indicated. In case of resistance – external steroids (prednisone), antibiotics and antibacterial drugs (from amoxicillin to ftivazid). Acute forms are enhanced with vascular drugs (xanthinol nicotinate) and antiallergic (loratadine).
Plaque parapsoriasis is a reason for dispensary observation of patients with mandatory supervision of a gastroenterologist. In case of resistance, a short course of hormone therapy (prednisone) is used. PUVA therapy in combination with therapeutic baths (Naphthalan, Matsesta) is indicated. Lichenoid parapsoriasis is resistant to any treatment, therefore, a dermatologist develops a therapeutic program for each patient individually. In extreme cases, antitumor drugs (metatrexate) are prescribed. Staying on the Dead Sea gives good results.
Proper diagnosis and timeliness of complex therapy is the key to long–term remission of parapsoriasis and a good quality of life. To avoid complications of parapsoriasis, timely and accurate diagnosis is necessary in order to exclude the classic lichen planus. Incorrect treatment, prescribed late, fixes a violation of vascular permeability, leads to the appearance of forms resistant to therapy, the formation of paraospenic scars at the site of rashes. In addition, the occurrence of itching is a reason for close attention to the course of the disease in order to prevent the malignancy of plaque parapsoriasis.