(A) What are the causes of psoriasis?
The cause of psoriasis is still unclear. It may be an immune disease mediated by T lymphocytes under the interaction of polygenic genetic factors and environmental factors, and neutrophils, keratinocytes, dendritic cells, endothelial cells and various chemokines are involved in the pathogenesis. Flu, mental stress, seasonal climate, trauma and certain drugs can trigger psoriasis, and smoking, drinking alcohol and eating spicy and other irritating foods may also aggravate the disease.
(2) How to diagnose psoriasis?
Clinically, we divide psoriasis into common type, joint type, pustular type and erythrodermic type, the most common of which is common type (more than 90%). The most common type is common psoriasis (more than 90%). Common psoriasis occurs on the scalp and the extremities, mainly manifesting as limited red plaques covered with silvery white scales, and a light red shiny translucent film can be seen when scraping off the scales, and small bleeding dots can be seen when scraping off the film. In addition, it can invade the glans, foreskin and oral cavity, and nail changes such as nail dimples, nail transverse grooves and nail plate hypertrophy are also very common and can be easily confused with onychomycosis.
In addition to the skin lesions of common psoriasis, it is also associated with painful deformities in the joints and even restricted movement, most commonly in the small joints at the ends of the fingers and toes. The joint symptoms are often aggravated or alleviated by the skin symptoms, and on x-ray the patient has mild hypertrophy of the distal finger joint edges, partly resembling rheumatoid arthritis changes. Psoriatic skin lesions, joint symptoms and negative rheumatoid factor are the basis for diagnosis. In addition, arthritic psoriasis is usually positive for HLA-B27, and together with ankylosing spondylitis and REITER disease is called HLA disease.
Pustular psoriasis is rare clinically and is generally classified as generalized or limited. Pustular psoriasis is often associated with the application of corticosteroids or topical irritation during the progressive phase of psoriasis. Generalized pustular psoriasis has an acute onset, often with dense superficial sterile pustules on top of large erythematous plaques throughout the body. Prior to the use of retinoids, the mortality rate was as high as 50%. Because pustules are sterile and are sometimes aggravated by antibiotics, antibiotics are generally not recommended unless there is clear evidence of infection. Restricted pustular psoriasis is usually limited to the palmoplantar or extremities, and the pustules may dry up and crust over spontaneously, recurring after the scabs have fallen off, often with pus accumulation under the nail, nail plate loss, or even limb destruction.
Erythrodermic psoriasis is often caused by the sudden discontinuation or rapid reduction of glucocorticosteroids after the external use of irritating drugs or long-term heavy intake of psoriasis vulgaris, and is also seen in the receding phase of pustular psoriasis. Patients have diffuse erythematous skin with a large amount of debris, accounting for more than 90% of the body surface area, often accompanied by fever, headache and superficial lymph node enlargement. Due to the destruction of the epidermal barrier, the erythrodermic type is prone to secondary infections, has a high mortality rate, and has a very persistent course. In addition, diseases such as eczema, connective tissue disease, mycosis fungoides or SEZARY syndrome can also present with erythrodermic changes, so patients with erythrodermic disease usually require a skin biopsy to identify the primary cause and provide symptomatic treatment.
Different types of psoriasis can be transformed into each other. Ms. Zhang mentioned in the article is a common type of psoriasis, which may also be transformed into an arthritic type after many years. Xiao Yang, on the other hand, started with common psoriasis, was treated with glucocorticoids and developed generalized pustular psoriasis after stopping the medication, and then showed limited pustular psoriasis in between treatments.
Psoriasis is not difficult to diagnose through clinical manifestations, rash characteristics, prevalent sites and the relationship between onset and seasons, of which observation of the morphology of the lesions is the key. However, the clinical manifestations of some patients are not typical and can be confused with stage II syphilis, discoid lupus erythematosus, seborrheic dermatitis, chronic eczema, neurodermatitis, onychomycosis, REITER disease or rheumatoid arthritis, etc. Skin biopsy and other relevant examinations are needed to determine the diagnosis. In addition, HIV infection with psoriasis-like lesions as the first manifestation has been observed in clinical practice.
(iii) How to treat psoriasis?
Psoriasis is one of the most common diseases in dermatology, which has a great physical and psychological impact on patients and has a high incidence in Europe and the United States. However, there has never been a cure in clinical treatment, with the main goal of relieving symptoms, clearing skin lesions and prolonging the relapse cycle.
For patients with mild to moderate psoriasis vulgaris, topical medications are usually used. Currently, commonly used drugs include vitamin D3 derivatives, retinoic acid cream, salicylic acid ointment, tacrolimus, and white petroleum jelly. Since long-term topical steroid hormones can induce pustular or erythrodermic psoriasis after discontinuation, we do not recommend their use.
For patients with moderate to severe psoriasis, in addition to topical medication, sometimes a combination of systemic therapy is required. The most commonly used treatment methods currently include.
(1) retinoids: e.g. Avelox, which is the first-line drug for pustular and erythrodermic psoriasis.
(2) Immunosuppressants: such as methotrexate, raglan polysaccharide, cyclosporine A and mescaline.
(3) Physiotherapy: such as PUVA (psoralen combined with long-wave ultraviolet light) and NB-UVB (narrow-spectrum medium-wave ultraviolet light).
(4) Biological agents: Biological agents developed in recent years are increasingly used in psoriasis treatment because of their good efficacy and tolerability. At present, biologics approved by FDA for the treatment of psoriasis include two major categories.
(i) T lymphocyte modulators, such as efalizumab and alfaset; (ii) TNF-Α antagonists, such as infliximab, etanercept and adalimumab; (iii) IL12/IL23 antagonists USTEKINUMAB/STELARA. adverse reactions such as tuberculosis, malignancy or thrombocytopenia have been reported for the above drugs, and the long-term efficacy and side effects need further observation.
(D) Frequently asked questions in outpatient clinics
1. What is the main difference between psoriasis and chronic eczema and neurodermatitis?
A: Psoriasis lesions are obviously congested, covered with scales, with film-dotted bleeding phenomenon, and usually do not itch or itching is not serious; while chronic eczema and neurodermatitis are usually not obviously congested or scaled, and itching is intense.
2.Is psoriasis contagious?
A: Psoriasis is not contagious. None of the lesions, scales or other samples of a psoriasis patient will cause psoriasis in direct contact. Familial psoriasis is often caused by genetic and environmental factors.
3. What can be achieved after psoriasis treatment?
A: Usually the lesions flatten and the scales subside after 2-6 weeks of treatment for common psoriasis, but the erythema can last for several months and often leaves pigmented spots after fading. Some of the erythema cannot even fade completely, and the majority of patients will relapse from time to time after the lesions have faded. In arthritic psoriasis, the joint symptoms may subside completely after treatment, and the lesions improve. Pustular and erythrodermic psoriasis often require long-term treatment, and some patients’ skin can be completely restored to normal or transformed to the common type, while some of them have recurrent relapses or even die during the treatment process.
4. Can psoriasis be cured?
A: Psoriasis is a chronic recurrent inflammatory disease. Current treatments can clear skin damage and relieve symptoms, but cannot control recurrence.