Acrodermatitis Chronica Atrophicans (ACA)

Introduction:

Acrodermatitis chronica atrophicans (ACA) European Lyme borreliosis ka late ya third stage hai, jo 'Borrelia afzelii' ke infection se hota hai. Is condition ko pehli baar 1883 mein identify kiya gaya aur 1902 mein describe kiya gaya. ACA ek progressive skin condition hai jisme fibrosis aur tissue atrophy hoti hai, jismein tissue paper jaise lagte hain.

Pathophysiology aur Etiology of Acrodermatitis Chronica Atrophicans (ACA)

Causative Agents:

ACA ka primary cause Borrelia afzelii hota hai, lekin Borrelia garinii (Borrelia burgdorferi sensu lato complex ka dusra genospecies) bhi implicated hai. Ye spirochetes humans mein tick ke kaatne se transfer hote hain aur Lyme borreliosis ka cause bante hain.

Borrelia afzelii

Pathophysiology:

Lyme disease ke doosre forms ke opposite, ACA khud se thik nahi hoti, jo ek unique pathogenic mechanism ko dikhata hai. Iska exact process abhi tak puri tarah se samjha nahi gaya, lekin kuch factors Borrelia ke skin mein persist karne ke liye zimmedar hain:

1. Spirochete Persistence:

Complement system ke resistance: Bacteria immune response se bache rehte hain.

Immune evasion: Spirochetes immunologically protected sites jaise endothelial cells aur fibroblasts mein chhupe rehte hain.

Antigenic variation: Pathogen apne surface antigens ko badal leta hai, jisse immune system effective response nahi de pata.

2. Immune Dysfunction:

Inadequate antibody response: ACA patients ke antibodies ka spectrum narrow hota hai aur protective antibodies nahi bante.
MHC Class II molecules ka downregulation: Langerhans cells (jo skin ke immune cells hote hain) mein in molecules ki kami T-cells activation ko impair karti hai.
Cytokine expression: Restricted cytokine profile jaise interferon-gamma ka absence, immune system ko infection se effectively fight karne se rokta hai.

3. Autoimmune Considerations: Cross-reactive antibodies tissue damage mein yogdan karte hain, lekin autoimmunity ka role abhi clear nahi hai. Chronicity ek aise immune response se judi ho sakti hai jo inadvertently host tissues ko harm karta hai.

Atrophic Skin Changes ka Pathogenesis:

Exact mechanism jo ACA ke characteristic skin atrophy ka cause banta hai wo samjha nahi gaya hai, lekin yeh mana jata hai ki periarticular sites low skin temperatures ya oxygenation ki wajah se Borrelia spirochetes ke liye favorable environment provide karate hain.

Clinical Presentation:

ACA aksar extremities pe aati hai, khaas taur pe extensor surfaces par, aur yeh do distinct phases mein hoti hai:

1. Inflammatory Phase:

Bluish-red skin discoloration aur swelling.
Soft, painless, poorly demarcated plaques jo milkar ek ho sakti hain.
Condition distal extremities se start hokar proximally spread hoti hai.

2. Atrophic Phase:

Mahino ya saalon baad hoti hai, jisme dark red ya brown discoloration hoti hai.
Skin thin, translucent, aur wrinkled ho jati hai, cigarette paper jaisi dikhai deti hai.
Prominent blood vessels, hair loss, aur sebaceous ya sweat glands ka absence hota hai.

Associated Symptoms:

Fibrotic nodules elbows, knees, aur adjacent joints pe form hote hain. Skin ulcerate kar sakti hai, aur malignant lesions develop ho sakte hain. Fingers aur toes mein deformities bhi ho sakti hain agar untreated chhod diya jaye.

Systemic Involvement:

Neurological involvement common hai, jisme sensory polyneuropathy symptoms jaise pain, paresthesia, aur paresis (partial paralysis) shamil hote hain.

Diagnosis:

Detailed clinical history, epidemiologic data, histopathology aur serologic testing ke through diagnosis kiya jata hai. ELISA, indirect immunofluorescence, aur Western blot assays commonly use kiye jaate hain Borrelia burgdorferi antibodies ko detect karne ke liye.

Management of Acrodermatitis Chronica Atrophicans (ACA)

Approach to Treatment:

1. Antibiotic therapy:

Oral antibiotics pehla-line treatment hoti hai jaise:
Doxycycline (100 mg do baar roz, 3-4 hafte ke liye).
Amoxicillin (500 mg teen baar roz, 3-4 hafte ke liye).

2. Advanced ya Systemic Lyme disease: Intravenous antibiotics jaise Ceftriaxone (2 g daily for 21-28 days) prefer kiye jaate hain.

3. Complications ka Management: Fibrotic nodules aur joint deformities agar untreated rehte hain toh physiotherapy helpful ho sakti hai.

4. Consultations for Systemic Involvement: Neurologic, rheumatologic, ya cardiac signs ke liye specialists ki zarurat hoti hai.

5. Coinfections aur Differential Diagnosis: ACA patients mein babesiosis ya ehrlichiosis jaise coinfections bhi ho sakte hain jo tick vector se transmitted hote hain.

Long-Term Monitoring:

Patients ko follow-up mein rakha jata hai disease ke progression aur treatment ke effectiveness ko monitor karne ke liye. Atrophic phase mein skin changes persist kar sakte hain.

Patient Education:

Patients ko batana chahiye ki ACA ka improvement weeks ya months le sakta hai. Lyme borreliosis ka early diagnosis aur treatment bahut zaroori hai, khaaskar endemic areas mein.

Prognosis:

Early treatment se complete recovery possible hai, lekin atrophic phase ke symptoms partial reverse ho sakte hain.

Conclusion:

ACA ek rare but significant manifestation hai Lyme borreliosis ka, jisme timely diagnosis aur appropriate treatment bahut zaroori hai taaki long-term complications se bacha ja sake. Antibiotic therapy effective hai, lekin early intervention irreversible damage se bacha sakti hai.