| Skin abscesses/cellulitis | S. aureus (often methicillin-susceptible S. aureus; sometimes MRSA) | Cold abscesses with minimal erythema/warmth; recurrent furunculosis | ∼50–80% (20, 21) | • Pathogen identification and antimicrobial susceptibility testing |
| • Prompt systemic antibiotics according to local resistance |
| • Surgical drainage |
| • Initiation of prophylactic antibiotics in patients with recurrent skin abscesses/cellulitis |
| Eczema-associated superinfection | S. aureus, β-hemolytic streptococci | Impetiginization of chronic eczema; crusted lesions | Very common (most have secondary bacterial infection of eczema at some point) (22) | • Pathogen identification and antimicrobial susceptibility testing |
| • Systemic or topical antibiotics plus anti-inflammatory eczema management and antiseptic baths |
| • Consider prophylactic antibiotics in patients with recurrent eczema-associated superinfection |
| Fungal skin infections | Candida spp., dermatophytes | Intertrigo, onychomycosis, tinea infections | Common, however, less systematically reported (22) | • Topical azoles or allylamides for limited infections |
| • Oral antifungal agents for extensive, recalcitrant, or nail involvement |
| Recurrent pneumonia | S. aureus, Streptococcus pneumoniae, Haemophilus influenzae, respiratory viruses | Recurrent pneumonias from infancy; often progress to bronchiectasis/pneumatoceles | ∼80–90% ever; >60% with ≥2 pneumonias (8, 22, 23) | • Pathogen identification and antimicrobial susceptibility testing |
| • Early, culture-guided systemic antibiotics |
| • Consider antibiotic prophylaxis and/or IGRT |
| Chronic lung infection | S. aureus, P. aeruginosa, Aspergillus fumigatus | Structural lung disease (bronchiectasis, pneumatoceles); chronic productive cough | Structural changes are present in ∼80–95% adults; chronic bacterial/fungal colonization is common (22) | • Prolonged, culture-guided systemic or inhaled antimicrobials when appropriate |
| • Intensive airway-clearance strategies |
| • Multidisciplinary care with involvement of pulmonology |
| • Consider referral to surgery for complications, e.g., pneumatoceles |
| CMC (oral, genital, nails) | Candida albicans and other Candida spp. | Recurrent oral thrush, angular cheilitis, vulvovaginal candidiasis, onychomycosis | ∼50–85% across cohorts (21, 22) | • Pathogen identification and antimicrobial susceptibility testing |
| • Topical azole or nystatin therapy for limited infections |
| • Systemic fluconazole (or alternate azole based on species and resistance) for refractory infection |
| • Consider long-term prophylaxis with systemic antifungal agent (e.g., fluconazole) |
| Severe disseminated infections (sepsis, deep abscesses) | Mainly S. aureus; occasionally gram-negatives | Invasive infections often from skin/lung focus | Less common; however, major cause of morbidity/mortality (22, 24) | • Urgent medical treatment, including broad-spectrum intravenous antibiotics with prompt de-escalation according to cultures and source |
| • Aggressive source control (e.g., drainage of abscesses) |
| • Review long-term prophylaxis |
| • Consider IGRT |
| • Consideration of HSCT in selected patients with severe, refractory infectious complications |