Related Subjects:
|Nikolsky's sign
|Koebner phenomenon
|Erythema Multiforme
|Pyoderma gangrenosum
|Erythema Nodosum
|Dermatitis Herpetiformis
|Lichen Planus
|Acanthosis Nigricans
|Acne Rosacea
|Acne Vulgaris
|Alopecia
|Vitiligo
|Urticaria
|Basal Cell Carcinoma
|Malignant Melanoma
|Squamous Cell Carcinoma
|Mycosis Fungoides (Sezary Syndrome)
|Xeroderma pigmentosum
|Bullous Pemphigoid
|Pemphigus Vulgaris
|Seborrheic Dermatitis
|Pityriasis/Tinea versicolor infections
|Pityriasis rosea
|Scabies
|Dermatomyositis
|Toxic Epidermal Necrolysis
|Stevens-Johnson Syndrome
|Atopic Eczema/Atopic Dermatitis
|Psoriasis
Molluscum contagiosum is a common, highly contagious viral skin infection caused by a DNA poxvirus. It is most frequently seen in children and young adults, presenting as small, skin-colored papules with central umbilication. While typically harmless and self-limiting, widespread or persistent cases may require medical intervention.
About
- Definition: Molluscum contagiosum is a viral infection characterized by the appearance of small, pearly papules with a central dimple (umbilication).
- Etiology: Caused by the molluscum contagiosum virus (MCV), a member of the Poxviridae family.
- Epidemiology: Most commonly seen in children, immunocompromised individuals, and sexually active adults. It is highly contagious and spreads through direct skin-to-skin contact or contaminated objects.
- Transmission: Spread via close personal contact, sharing of towels or clothing, and fomites. In adults, it can be transmitted sexually.
Studies indicate that molluscum contagiosum lesions are small, skin-colored papules with central umbilication. These lesions are most frequently observed on the trunk, limbs, and, in adults, the genital area.
Clinical Features
- Lesion Appearance: Small, pearly-topped papules with a central depression (punctum).
- Size: Typically 2-6 mm in diameter but can enlarge to 10-20 mm.
- Distribution: Commonly found on the trunk, limbs, face (especially in children), and genitalia (in adults).
- Koebner Phenomenon: Lesions may appear along sites of skin trauma or irritation.
- Pruritus: Mild to moderate itching is common, especially in individuals with dry skin or those exposed to heat and sweating.
- Systemic Symptoms: Generally absent, but widespread molluscum in adults should prompt evaluation for immunosuppression, including HIV infection.
- Atopic Dermatitis: More common and extensive in individuals with atopic eczema due to compromised skin barrier.
Clinical Signs
Investigations
- Clinical Diagnosis: Primarily based on the characteristic appearance of lesions.
- Skin Biopsy: Rarely needed but may be performed to exclude other dermatological conditions like psoriasis or eczema if the presentation is atypical.
- KOH Test: Can help rule out fungal infections such as tinea corporis (ringworm) which may mimic the herald patch in early stages.
- HIV Testing: Consider in adults with widespread or persistent molluscum contagiosum to rule out immunosuppression.
Differential Diagnosis
- Tinea Corporis (Ringworm): Fungal infection presenting with scaly, erythematous patches but typically lacks central umbilication and follows a ring-like pattern.
- Secondary Syphilis: Presents with a widespread rash that can mimic molluscum contagiosum; confirmed with serological testing (e.g., RPR, FTA-ABS).
- Eczema (Atopic Dermatitis): Features red, scaly patches but is usually more pruritic and associated with a history of atopic conditions.
- Granuloma Annulare: Presents as ring-shaped lesions but lacks central umbilication.
Management
- Observation: Molluscum contagiosum is self-limiting and often resolves spontaneously within 6 to 18 months.
- Symptomatic Treatment:
- Antihistamines: Oral antihistamines (e.g., loratadine, diphenhydramine) can alleviate itching and improve sleep.
- Topical Treatments:
- Topical Corticosteroids: Mild corticosteroids like hydrocortisone cream can reduce inflammation and itching.
- Emollients: Regular use of moisturizers helps soothe dry, irritated skin and reduce scaling.
- Local Treatments:
- Cryotherapy: Liquid nitrogen application by a general practitioner or dermatologist until lesions clear.
- Curettage: Scraping off lesions with a sharp instrument after local anesthetic injection.
- Imiquimod: An immune response modifier used off-label; however, it is not licensed for molluscum contagiosum and is generally ineffective.
- Specialist Referral: Eye specialists for lesions on the eyelids.
- Systemic Treatment:
- HAART: In HIV-positive patients, initiation of Highly Active Antiretroviral Therapy can lead to resolution of molluscum contagiosum.
- Preventive Measures:
- Avoid sharing personal items such as towels, clothing, and bedding to reduce transmission risk.
- Maintain good personal hygiene practices.
- Inform patients that children with molluscum contagiosum do not need to be excluded from school or swimming pools.
Prognosis
- Self-Limiting: Molluscum contagiosum typically resolves without treatment within 6 to 18 months.
- Complete Recovery: Most patients recover fully without residual skin changes.
- Post-Inflammatory Hyperpigmentation/Hypopigmentation: May occur, especially in individuals with darker skin tones, but usually fades over time.
- Recurrence: Rare, occurring in less than 3% of cases.
Conclusion
Molluscum contagiosum is a benign and highly contagious viral skin infection that primarily affects children and young adults. While it often resolves spontaneously, various treatment options are available to expedite clearance and alleviate symptoms. Proper diagnosis and management are essential, particularly in immunocompromised individuals, to prevent complications and transmission.
References
- Harmon, A. J., & Gupta, A. K. (2004). Pityriasis rosea: An update. Dermatology, 208(2), 145-152.
- Mayo Clinic. Molluscum Contagiosum. Available at: https://www.mayoclinic.org
- National Institutes of Health (NIH). Molluscum Contagiosum. Available at: https://www.ncbi.nlm.nih.gov
- World Health Organization (WHO). Skin Conditions. Available at: https://www.who.int
- American Academy of Dermatology Association. Molluscum Contagiosum. Available at: https://www.aad.org