Scabies: Clinical Presentation, Diagnostic Evaluation, Management, and Outcomes – A Case Report

Abstract

Scabies is a highly contagious parasitic skin infestation caused by Sarcoptes scabiei var. hominis. It commonly presents with intense nocturnal itching, papular eruptions, and characteristic burrows involving the interdigital spaces, wrists, axillae, and genital regions. Delayed diagnosis may lead to secondary bacterial infections, widespread transmission, and significant impairment in quality of life.

We present the case of a 28-year-old male who presented with generalized itching and multiple excoriated papular lesions involving the hands, wrists, abdomen, and groin for 4 weeks. Clinical examination and dermoscopic evaluation confirmed the diagnosis of scabies. The patient was managed with topical permethrin therapy, antihistamines, hygiene measures, and simultaneous treatment of close contacts, resulting in significant clinical improvement.

This case highlights the importance of early recognition, prompt treatment, and preventive strategies in controlling scabies transmission and reducing complications.

Introduction

Scabies is a common ectoparasitic infestation caused by the mite Sarcoptes scabiei. The female mite burrows into the superficial layers of the skin, causing hypersensitivity reactions that result in severe itching and inflammatory skin lesions.

Scabies affects individuals of all age groups and is particularly prevalent in crowded living conditions, institutions, and areas with poor hygiene. Transmission mainly occurs through prolonged skin-to-skin contact, although indirect transmission through contaminated clothing and bedding may also occur.

Important risk factors include:

• Overcrowding
• Poor personal hygiene
• Close household contact
• Immunocompromised state
• Institutional living
• Low socioeconomic conditions

Patients commonly present with:

• Severe nocturnal itching
• Papules and vesicles
• Burrows in interdigital spaces
• Excoriations due to scratching
• Secondary bacterial infection

Delayed diagnosis may lead to persistent infestation, eczema, impetigo, cellulitis, and community outbreaks. Early diagnosis and simultaneous treatment of contacts are essential for disease control.

Case Report

Patient History

A 28-year-old male presented to the dermatology outpatient department with:

• Severe itching for 4 weeks
• Increased itching during night
• Multiple red raised lesions over hands and abdomen
• Sleep disturbance due to pruritus

The patient reported that two family members had similar symptoms.

There was no history of:

• Drug allergy
• Chronic skin disease
• Diabetes mellitus
• Recent travel

Clinical Examination

General Examination

• Afebrile

• Pulse rate: 82/min

• Blood pressure: 118/76 mmHg

• Systemically stable

Dermatological Examination

Cutaneous examination revealed:

• Multiple erythematous papules

• Excoriated lesions over wrists and abdomen

• Burrows in interdigital spaces
• Papulovesicular lesions in groin region
• Scratch marks with mild crusting

No mucosal involvement was noted.

Clinical Evaluation

Differential Diagnosis

The following conditions were considered:

• Atopic dermatitis
• Contact dermatitis
• Papular urticaria
• Fungal infection
• Scabies

The presence of nocturnal itching, burrows, and family history strongly suggested scabies infestation.

Investigations

Laboratory Findings

• Complete blood count: Normal
• Blood sugar levels: Normal
• No eosinophilia detected

Dermoscopy

Dermoscopy revealed:

• Characteristic “delta wing” appearance
• Burrow tracks
• Mite visualization

Skin Scraping Examination

Microscopic examination demonstrated:

• Scabies mites
• Eggs
• Fecal pellets (scybala)

These findings confirmed the diagnosis of scabies.

Diagnosis

Based on clinical findings and microscopic examination, a diagnosis of Classical Scabies Infestation was established.

Management and Outcome

Initial Management

The patient was advised:

• Personal hygiene maintenance
• Washing clothes and bedding in hot water
• Avoiding close skin contact
• Simultaneous treatment of family members

Definitive Treatment

The patient received:

• Topical permethrin 5% cream overnight application

• Oral antihistamines for itching

• Mild topical corticosteroid for inflammation

Treatment was repeated after one week.

Follow-Up and Clinical Course

At 2 Weeks

• Significant reduction in itching

• Decrease in papular lesions

• Improved sleep quality

At 4 Weeks

• Complete resolution of active lesions

• No fresh burrows

• Minimal residual pigmentation

At 6 Weeks

• No recurrence of symptoms

• Family members also improved after treatment

• Patient resumed normal daily activities

​​​​​​​

Discussion

Pathophysiology

Scabies results from infestation by Sarcoptes scabiei mites that burrow into the epidermis and trigger delayed hypersensitivity reactions.

Important pathological mechanisms include:

• Mite burrowing within skin
• Immune-mediated inflammatory response
• Hypersensitivity to mite proteins and feces
• Secondary bacterial colonization due to scratching

Persistent scratching may cause skin barrier disruption and secondary infection.

Epidemiology

Important epidemiological features include:

• Common in tropical and resource-limited regions
• Affects all age groups
• Highly contagious within households
• Increased prevalence in overcrowded settings
• Frequent outbreaks in schools and institutions

Scabies remains an important global public health concern.

Clinical Manifestations

Common symptoms include:

• Intense nocturnal pruritus

• Burrows and papules

• Vesicular lesions

• Excoriations and crusting

• Secondary bacterial infection

Commonly involved sites include:

• Finger webs
• Wrists
• Axillae
• Waistline
• Groin

Diagnostic Considerations

Diagnosis is primarily clinical but may be confirmed through:

1. Dermoscopy

2. Skin scraping microscopy

3. Adhesive tape test

4. Histopathology in selected cases

Dermoscopy significantly improves rapid bedside diagnosis.

Treatment Modalities

Medical Management

Conservative measures include:

• Personal hygiene

• Contact tracing

• Environmental decontamination

• Washing contaminated fabrics

Pharmacological Therapy

Definitive treatment options include:

• Permethrin 5% cream
• Oral ivermectin
• Sulfur ointment
• Benzyl benzoate lotion
• Antihistamines for pruritus

Simultaneous treatment of close contacts is essential to prevent reinfestation.

Complications

Potential complications include:

• Secondary bacterial infection
• Impetigo
• Cellulitis
• Post-scabetic eczema
• Crusted scabies
• Community outbreaks

Untreated scabies may significantly affect quality of life and mental well-being.

Prognosis

Prognosis is excellent with early diagnosis and proper treatment.

Important prognostic factors include:

• Treatment adherence
• Simultaneous contact management
• Personal hygiene
• Prevention of reinfestation
• Early recognition of recurrence

Most patients recover completely with timely therapy.

Conclusion

Scabies is a highly contagious parasitic dermatological disorder caused by infestation with Sarcoptes scabiei var. hominis. The condition remains a significant public health concern, particularly in crowded living conditions, resource-limited settings, schools, nursing homes, and among individuals with close household contact. Transmission primarily occurs through prolonged skin-to-skin contact, although indirect spread through contaminated clothing, towels, bedding, and fomites may also occur. Clinically, patients commonly present with severe nocturnal pruritus, erythematous papules, excoriated lesions, vesicles, nodules, and characteristic serpiginous burrows, most frequently involving the interdigital spaces, flexor aspects of the wrists, axillae, waistline, buttocks, and genital region. Persistent itching and sleep disturbance often lead to considerable physical discomfort, psychological stress, and impaired quality of life. If left untreated, scabies may predispose patients to secondary bacterial infections such as impetigo, cellulitis, and, in severe cases, post-streptococcal complications including glomerulonephritis.

This case emphasizes the importance of maintaining a high index of suspicion in patients presenting with generalized pruritus and typical lesion distribution, especially when there is a history of similar symptoms among close family members or contacts. Accurate diagnosis relies on careful clinical evaluation supported by dermoscopic identification of the classic “delta wing” sign and microscopic confirmation of mites, eggs, or scybala from skin scrapings. Early and appropriate treatment with anti-scabetic agents such as permethrin or ivermectin can rapidly control infestation and prevent further transmission. Equally important is the simultaneous treatment of household members and close contacts, even if asymptomatic, to minimize the risk of reinfestation. Comprehensive patient counseling regarding personal hygiene, environmental cleaning, washing of clothes and bedding in hot water, and adherence to therapy is essential for successful eradication. This case further highlights the role of patient education, follow-up assessment, and preventive public health measures in reducing recurrence, limiting outbreaks, and ensuring complete clinical recovery.

References

1. Chosidow O. Scabies and pediculosis. https://pubmed.ncbi.nlm.nih.gov/15459669/
2. Engelman D, Cantey PT, Marks M, et al. The public health control of scabies. https://pubmed.ncbi.nlm.nih.gov/31449872/
3. Walton SF, Currie BJ. Problems in diagnosing scabies. https://pubmed.ncbi.nlm.nih.gov/15304108/
4. Thomas J, Carson CF, Peterson GM, et al. Therapeutic potential of tea tree oil for scabies. https://pubmed.ncbi.nlm.nih.gov/22453108/
5. World Health Organization. Scabies Fact Sheet. https://www.who.int/news-room/fact-sheets/detail/scabies
6. American Academy of Dermatology. Scabies Overview. AAD Scabies Overview

Read more such content on @ Hidoc Dr | Medical Learning App for Doctors