Viral Meningitis

The most common cause of meningitis overall, typically enteroviruses (coxsackievirus, echovirus), also HSV-2 (particularly with recurrent, "Mollaret's" meningitis), VZV, mumps (in unvaccinated populations), and HIV seroconversion.

Generally self-limiting with a benign course, in sharp contrast to bacterial meningitis, making the distinction between the two the central diagnostic task.

CSF shows a lymphocytic pleocytosis (though a neutrophilic predominance can occur very early in enteroviral meningitis, potentially confounding initial interpretation), normal glucose, and normal or mildly elevated protein, a pattern clearly distinct from the bacterial pattern described in the Meningitis entry.

Enterovirus PCR of CSF is the primary confirmatory test where available; HSV/VZV PCR where clinically relevant.

Supportive care: analgesia, antiemetics, hydration; most cases resolve within 7 to 10 days
Empirical bacterial meningitis treatment should be started and only stopped once bacterial meningitis is confidently excluded (reassuring CSF pattern, negative Gram stain, clinical improvement, and, where used, a negative bacterial PCR panel), given the overlap in early presentation and the catastrophic consequence of missing bacterial disease
HSV meningitis (as opposed to encephalitis) is generally self-limiting and antiviral treatment is not routinely required unless the presentation suggests concurrent encephalitis or the patient is immunocompromised
Admission for observation is reasonable pending exclusion of bacterial disease, particularly where the clinical picture is not yet clearly reassuring

Referral: infectious disease for atypical or recurrent presentations, or diagnostic uncertainty.

Tinea Corporis

Also known as: Ringworm

Dermatophyte infection of glabrous (non-hairy) skin , Trichophyton rubrum most common, also Microsporum species (zoophilic; animal contact, tends to cause more inflammatory reaction).

Transmission via direct contact (person, animal, fomites) or autoinoculation from another infected site (feet, nails, scalp).

Annular ("ring-shaped") erythematous plaque with raised, scaly, active advancing border and central clearing, mildly itchy. May have multiple lesions, can coalesce.

Consider zoonotic source (pets : cats/dogs, particularly kittens) if inflammatory/pustular presentation.

Tinea incognito: atypical, less scaly, poorly demarcated appearance from inappropriate topical steroid use ; masks classic features, important to recognize.

Clinical for typical presentation.

KOH microscopy of skin scraping from active border: confirms branching hyphae; recommended before treatment, especially if diagnosis uncertain or steroid pre-treatment has altered appearance.

Fungal culture: species identification if needed (recurrent/treatment-resistant/zoonotic source investigation).

Differentials: nummular eczema (no central clearing, more uniform), psoriasis (thicker scale, extensor distribution), pityriasis rosea, granuloma annulare (no scale), erythema migrans (LyLym; larger, less scaly, expanding).

Topical antifungal ; first-line for localized disease: terbinafine cream od-bd × 1-2 weeks, or clotrimazole/miconazole bd × 2-4 weeks (continue treatment ~1 week beyond visible clearance)
Avoid topical steroid monotherapy ; worsens/masks infection (tinea incognito); combination steroid-antifungal products generally discouraged for the same reason
Oral therapy if extensive, multiple sites, immunocompromised, or failed topical treatment: terbinafine 250mg od × 2-4 weeks, or itraconazole 100-200mg od × 2-4 weeks
Identify and treat source: concurrent tinea pedis/unguium (autoinoculation), pet examination/veterinary treatment if zoonotic source suspected
Hygiene measures: avoid sharing towels/clothing, keep skin dry, launder bedding/clothing

Referral: dermatology for extensive/recurrent/treatment-resistant disease, diagnostic uncertainty.

Viral Meningitis

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management