Alopecia areata: pathogenesis, diagnosis, treatment

Natalya SACHUK, head of the Farmosa medical center, dermatovenerologist, trichologist, dermato-oncologist, cosmetologist, member of the All-Ukrainian Academy of Dermatovenerology, Association of Psoriasis, Association of Preventive and Anti-Aging Medicine, Society of Trichologists of Ukraine, All-Ukrainian Association of Dermatovenerologists and Cosmetologists (Ukraine)

In my case, these are the most difficult, but also the most beloved patients, because you are their last hope, and for you they are the reason to extract all your knowledge and experience from your memory, overcome yourself, have a great desire to help and see how despair is replaced by happiness .

Before moving on to the analysis of clinical cases, let's update the theoretical knowledge about alopecia areata .

Alopecia areata (AA) is a chronic autoimmune inflammatory disease with a genetic predisposition, characterized by damage to the hair follicles, and in severe cases, to the nail plates, persistent or temporary non-scarring hair loss

CLASSIFICATION

According to ICD-10, alopecia areata is divided into:

• L63.0 – total alopecia ;
• L63.1 – alopecia universalis ;
• L63.2 – patchy baldness (ribbon-shaped) ;
• L63.8 – another alopecia areata .

Depending on the volume and type of baldness, the following clinical forms are distinguished:

• local (limited) ;
• subtotal ;
• total ;
• universal

Other forms of GA are:

• multifocal (mesh) arrangement of alopecia areas;
• ophiasis ;
• inverse ophiasis (sisapho) ;
• diffuse form .

ETIOLOGY AND PATHOGENESIS

It is assumed that the main cause of hair loss in alopecia areata is autoimmune damage to the hair follicle , which leads to a violation of the immune tolerance of the cells that form the follicle and the cessation of specific reception from its hair papilla.

Predisposition to GA is genetic. Some patients have a family history of the disease, but relatives are not always able to recognize this type of alopecia, and the disease remains undiagnosed. There is an association between GA and certain class II HLA alleles, especially DQB1*03 and DRB1*1104. HLA alleles DQB1*0301(HLA-DQ7) and DRB1*1104 (HLA-DR11) may be associated with total and universal alopecia.

The main triggering factors of the disease are the processes occurring in the immune system and everything that affects it: vaccination, viral diseases, especially the herpetic group of viruses, candidiasis, streptococcal and staphylococcal infections, other infectious diseases, taking antibacterial and immunostimulating drugs, anesthesia, stress etc. The immune system tries to cope with the infection and attacks the skin and its appendages, this is due to the general structure of antibodies.

Other autoimmune diseases are associated with alopecia areata: autoimmune thyroiditis, vitiligo, atopic dermatitis

Most often, autoimmune processes in other organs develop under the influence of the same causes of GA, some debut earlier, and some later. The body's readiness for autoimmune processes is genetic and partly depends on the intensity of the influence of unfavorable factors on the immune system.

SYMPTOMS, COURSE

With a local (limited) form of HA, one or more rounded foci of alopecia are determined on the scalp.

In the subtotal form of HA, more than 40% of hair is lost on the scalp. Small and large lesions merge into larger areas.

With ophiasis, alopecia foci have a ribbon-like shape and cover the entire marginal zone of hair growth in the occipital and temporal regions. The back of the head, the area behind the ears, and the frontal part are most often affected.

With inverse ophiasis (sisapho), the foci of alopecia are ribbon-shaped and spread to the fronto-parietal and temporal regions.

The diffuse form of HA is characterized by partial or complete diffuse hair thinning on the scalp, which resembles diffuse alopecia.

In the total form of HA, complete loss of terminal hair on the scalp is observed. All foci merge.

With the universal form of HA, hair is absent on the skin of the scalp, in the area of ​​eyebrow growth, eyelashes, on the skin of the torso, in the area of ​​the limbs and genitals.

There are several stages of the pathological process : a progressive stage, a stage of stabilization and reverse development of the lesion. Subjective symptoms are most often absent.

Progression stage

Patients complain of itching, burning or pain at the sites of potential lesions; the complaints soon subside. The skin is not changed, there is no peeling or redness. Around the lesions there is a characteristic hair tension test at a distance of 1–2 cm, which indicates the progression of the process of hair loss and the expansion of baldness lesions, which are initially round or oval in shape. When viewed by a camera, proximally narrowed and distally wide hair in the shape of an exclamation mark is characteristic due to atrophy of vascular loops and atrophy of the hair follicle, damage to fibroblasts that have undergone an immune attack.

Stationary stage

Around the area of ​​alopecia, the area of ​​“loose hair” is no longer defined, the skin in the area is unchanged. There is no growth in the central part of the lesion; the presence of black dots is characteristic, indicating the melting (destruction) of the hair follicle inside the skin.

Regression stage

There is no area of ​​loose hair, and the skin is also unchanged. In the area of ​​alopecia, growth of vellus - vellus depigmented hair, as well as partial growth of terminal pigmented hair is observed. When hair regrowth occurs, the original hair is usually hypopigmented, but color usually returns over time.

In patients with GA, specific dystrophic changes in the nails may be observed - punctate dystrophy, trachyonychia, Beau's lines, onychorrhexis, thinning or thickening of the nails, onychomadesis, koilonychia, punctate or transverse leukonychia, red spotted lunulae, which indicates the activity of a pronounced autoimmune process

In approximately half of patients, even without treatment, spontaneous remission is observed within a year. Often, approximately 85% of patients experience more than one episode of the disease; each time, the lesions, as a rule, become larger and take longer to heal.

With the development of HA before puberty, the probability of developing total alopecia is 50%, this is presumably due to an immature immune system. With total and universal alopecia, the probability of complete recovery is less than 10% in the absence of correct and timely treatment

The prognosis is aggravated by early age, family history, and the presence of concomitant autoimmune pathology.

DIAGNOSTICS

The diagnosis of GA is established based on the clinical picture of the disease:

• the presence of foci of alopecia on the skin with clear boundaries, without a glow specific for fungi in a Wood’s lamp;
• the presence of stumps of hair in the lesion in the form of an exclamation mark and a “loose hair zone” at the border of the lesion (active stage);
• detection during microscopic examination of hair epilated from the lesion of dystrophic proximal ends in the form of a “broken rope”;
• the presence of light vellus or gray hair in the growth area (in the regression stage); sometimes along one edge of the lesion there are fragments of hair in the form of an exclamation mark, and on the opposite - the growth of vellus;
• detection during examination of nails of signs of onychodystrophy - thimble-shaped indentations, longitudinal striations, changes in the form of wavy patterns of the free edge;
• detection during trichoscopy (dermatoscopy of the scalp) of “yellow dots”, cadaverized hair, hair in the form of exclamation marks.

With these signs, the skin is without visible inflammatory changes.

Identification of dystrophic hair ends is a pathognomonic sign of alopecia areata

In case of a doubtful diagnosis , as well as before prescribing treatment, a number of laboratory tests are recommended:

• microscopic examination of skin and hair for the presence of pathogenic fungi;
• microscopic examination of hair epilated from the marginal zone of the lesion (detection of dystrophic hair ends - a sign pathognomonic for HA );
• microvideoscopy of the skin with a camera to identify symptoms characteristic of HA;
• diagnostic skin biopsy. Histologically, HA is characterized by a predominantly T-cell inflammatory infiltrate in and around the anagen hair follicle bulbs. However, the histopathological signs of GA depend on the stage of the disease; in the case of a chronic course of the disease, classical signs may be absent;
• clinical blood test;
• serological studies to exclude systemic lupus erythematosus and syphilis;
• determining the level of cortisol in the blood and testing 24-hour urine for cortisol (when planning treatment with systemic glucocorticoids - before treatment, during treatment, 4 weeks after its completion);
• biochemical blood test: ALT, AST, total protein, bilirubin, cholesterol, insulin, alkaline phosphatase, glucose;
• plain radiography of the skull (to exclude space-occupying formations in the sella region);
• blood test for thyroid hormones (T3-free, T4-free, TSH, AT to TPO, AT to TG) to exclude thyroid pathology, for prolactin to exclude prolactinemia;
• IgM and IgG to herpes, cytomegalovirus, Epstein-Barr, toxoplasmosis, giardia, helminths;
• IgE general;
• throat culture and subsequent treatment of ENT infections;
• rheovasoencephalogram (REG) – recommended for common forms of HA in children under 12 years of age in order to diagnose possible circulatory disorders in the cerebral vascular system.

After tests, according to indications , consultations with infectious disease specialists, an immunologist, and an endocrinologist are prescribed.

Differential diagnosis

Differential diagnosis is carried out with trichotillomania, diffuse toxic alopecia, trichophytosis of the scalp, cicatricial alopecia.

In trichotillomania, alopecia lesions have an irregular shape and are usually located in the temples, crown, eyebrows and eyelashes. In the central part of the lesion, terminal hair growth is often observed. In the outbreak, hair can be broken off at different lengths. Microscopic examination reveals hair roots in the anagen or telogen stage; dystrophic hair is absent.

Diffuse toxic alopecia is usually associated with acute toxic conditions - poisoning with heavy metal salts, chemotherapy, taking cytostatics, prolonged increase in body temperature to 39 ° C and above.

In case of trichophytosis of the scalp, during examination, an inflammatory ridge is detected along the periphery of the lesion and the presence of “stumps” - hair broken off at a level of 2-3 mm from the surface of the skin. The disease may be accompanied by inflammation and peeling, which, as a rule, is not observed with GA. Microscopic examination of hair fragments for fungi reveals fungal drusen inside or outside the hair shaft.

With cicatricial alopecia, the skin in the affected area is shiny, the follicular apparatus is not expressed, and there is no skin pattern. Clinical manifestations of cicatricial alopecia sometimes cause diagnostic difficulties; in this case, histological examination is recommended.

In children with a congenital single area of ​​baldness in the temporal zone, a differential diagnosis should be made with temporal triangular alopecia .

GA in cases of damage to the frontal hairline and temporal zone requires the exclusion of frontal fibrous alopecia - scarring hair loss that occurs mainly in postmenopausal women. The disease may be accompanied by perifollicular erythema and desquamation, which are not observed with GA.

CLINICAL EXAMPLES OF TREATMENT OF HA

Let us analyze the treatment process using a specific clinical case. Over the 17 years of working as a trichologist, I had a huge number of patients in my practice, and the greatest aggression occurred in childhood, when many things cannot be done and the main thing remains the identification and treatment of trigger factors, thanks to which I successfully obtained positive and long-lasting results.

Clinical case: boy, 11 years old. He was admitted to the clinic with complaints of lack of hair on the scalp, eyebrows and eyelashes.

From early childhood there were several episodes of focal hair loss, which resolved spontaneously with regrowth. At a certain point, during an exacerbation, the lesions merged, eyelashes and eyebrows fell out and never recovered. Long wanderings to dermatologists did not yield any results, and external treatment (tincture of capsicum, vitamins, darsonvalization) did not help.

They came to me at Farmosa MC with a general blood test and biochemistry. And that's all that was in the patient's hands. As a result of a full examination according to the standard internal clinical protocol, many disorders were discovered: lymphocytosis, monocytosis, a high level of IgG to the Epstein-Barr cytomegalovirus, bacterial culture from the throat showed streptococcus aureus with sensitivity to cephalosporins, Klibsiella pneumoniae, a high level of blood cortisol, thyroid disorders glands – increased ATPO. Upon further examination - chronic tonsillitis, pharyngitis, slightly enlarged submandibular lymph nodes. Ultrasound of all organs is normal.

On examination, nails with point onychodystrophy in the form of a thimble were found. Microvideoscopic examination was in favor of GA; scrapings were made for fungi; examination with a Wood's lamp was unremarkable. The patient was referred to a pediatric infectious disease specialist for treatment of a latent form of herpesvirus infection, to an endocrinologist, and to an ENT doctor for oral sanitization.

The clinic underwent red laser therapy, UVB 311 nm, up to 20 procedures in courses. As a result, vellus blond hair began to grow only on the scalp.

Antihistamine therapy was prescribed, calcium citrate, vitamin C, selenium, biotin 5 mg/day, which led to a sharp decrease in the levels of ATPO and cortisol in the blood, after which eyelashes and eyebrows began to grow. Then, a diluted SC GCS was added to the outer part of the head once every 14 days, which made it possible to obtain a pronounced positive result.

The patient continued to take long-term antiviral and antihistamine therapy from an infectious disease specialist. Now the child is being monitored by all related specialists under my supervision. Years of negative efforts have been successful. Cortisol is constantly monitored. The nails became smooth, onychodystrophy disappeared (they were a sign of a decrease in the autoimmune process and the load of the bulbs with antibodies).

New hair appeared at great speed, and every 14 days of control were incredibly joyful. Today, the regional lesions are growing at a slower rate; according to tests and instrumental examination, the child is absolutely healthy.

Observation and supportive treatment will continue for two years.

Our trichology center treats many patients with a similar history, including adults, and thanks to a thorough examination and consultation with related specialists, the autoimmune load of the body due to infectious pathologies was mainly identified. And persistent treatment has yielded many positive results in both children and adults.

In the first place, first of all, there should be identification of the causes and concomitant pathologies, a careful study of which makes it possible to immediately determine from the anamnesis what is the leading factor in the development of GA in your patient.

First published in ​"Les Nouvelles Esthétiques Ukraine" No. 6 (112) 2018