AIM • STEP 10
Student Memory Support
Viral, Bacterial and Fungal Skin Infections
Final Year MBBS • High-yield memory reinforcement and last-minute revision
1. High-Yield Flashcards
Tap each question to reveal the answer.
What lesion pattern strongly suggests chickenpox?
Successive crops of lesions with macules, papules, vesicles and crusts present together.
What distribution is typical of herpes zoster?
A painful unilateral dermatomal vesicular eruption.
Which virus causes common cutaneous warts?
Human papillomavirus (HPV).
What is the characteristic morphology of molluscum contagiosum?
Smooth, dome-shaped papules with central umbilication.
What type of skin infection can suggest advanced HIV-related immunosuppression?
Severe, recurrent, persistent or unusually extensive infectious dermatoses.
What is the classic appearance of non-bullous impetigo?
Superficial erosions with honey-colored crusting.
How does a furuncle differ from folliculitis?
A furuncle is a deeper painful follicular infection with abscess formation.
What finding is particularly important in suspected leprosy?
Sensory loss in a skin lesion with possible peripheral nerve thickening.
What lesion is typical of primary syphilis?
A painless indurated chancre.
Which organism is associated with pityriasis versicolor?
Malassezia species.
What is the typical morphology of tinea corporis?
An itchy annular plaque with an active scaly edge and relative central clearing.
What appearance suggests candidal intertrigo?
A moist erythematous fold rash with peripheral satellite pustules.
What is the key treatment principle for localized superficial dermatophytosis?
Topical antifungal therapy is appropriate for localized glabrous skin infection.
Why can topical corticosteroid monotherapy mislead in dermatophytosis?
It can suppress inflammation while the fungal infection continues to spread, producing steroid-modified tinea.
What management principle is important in recurrent candidiasis?
Treat the fungal infection and assess or correct predisposing factors such as moisture, diabetes, antibiotic exposure or impaired immunity.
2. Mnemonics
Mnemonic Title:
Common Wart Types
Mnemonic Word:
CPFG
Meaning:
Common → Plantar → Flat/plane → Genital warts.
Mnemonic Title:
Pyogenic Infection Depth
Mnemonic Word:
F-F-C
Meaning:
Folliculitis → Furuncle → Carbuncle: superficial follicle → deeper abscess → interconnected deep infection.
Mnemonic Title:
Superficial Fungal Recognition
Mnemonic Word:
PDC
Meaning:
Pityriasis versicolor → pigment change with fine scale; Dermatophyte → annular scaly edge; Candida → moist erythema with satellite lesions.
3. Memory Tables
Viral Lesion Comparison
| Condition | Key morphology | Key clue |
|---|---|---|
| Chickenpox | Vesicles in different stages | Successive generalized crops |
| Herpes zoster | Grouped vesicles | Painful unilateral dermatome |
| Wart | Rough hyperkeratotic papule | HPV-related epidermal proliferation |
| Molluscum | Smooth umbilicated papule | Autoinoculation possible |
Superficial Fungal Comparison
| Condition | Typical clue | Management principle |
|---|---|---|
| Pityriasis versicolor | Fine scale with pigment alteration | Topical antifungal for localized disease |
| Dermatophytosis | Annular plaque, active scaly edge | Topical for limited skin; deeper sites may need systemic therapy |
| Candidiasis | Moist erythema with satellite pustules | Antifungal plus correction of moisture/risk factors |
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Chickenpox shows successive crops, so lesions at different stages coexist.
- Herpes zoster follows a unilateral sensory dermatome and may cause persistent neuropathic pain.
- Warts are HPV-related and spread by direct contact or contaminated surfaces.
- Molluscum contagiosum produces smooth centrally umbilicated papules.
- Honey-colored crusting strongly suggests non-bullous impetigo.
- Carbuncles are deeper interconnected staphylococcal infections and may require drainage.
- Sensory loss in a skin lesion with nerve thickening strongly supports leprosy.
- A painless indurated chancre suggests primary syphilis; systemic rash may occur in secondary disease.
- Dermatophytes infect keratinized tissues: skin, hair and nails.
- Candidiasis is promoted by moisture, antibiotics, diabetes and impaired immunity.
- Residual pigment change after pityriasis versicolor treatment does not necessarily mean persistent active infection.
5. Clinical Memory Hooks
Painful unilateral band of vesicles → think herpes zoster and sensory dermatome involvement.
Smooth pearly papules with central depression → think molluscum contagiosum.
Hypopigmented patch with sensory loss → think leprosy and examine peripheral nerves.
Annular itchy lesion worsened by topical steroid alone → think steroid-modified dermatophyte infection.
Moist skin-fold rash with satellite pustules → think candidiasis plus an underlying moisture or metabolic risk factor.
6. High-Yield Exam Points
- ⭐ Painful unilateral dermatomal vesicles strongly support herpes zoster.
- ⭐ Central umbilication is the key morphology of molluscum contagiosum.
- ⭐ Honey-colored crusting is a classic clue to non-bullous impetigo.
- ⭐ Sensory loss within a skin lesion plus peripheral nerve thickening is highly suggestive of leprosy.
- ⭐ Annular scaling with central clearing strongly supports dermatophytosis.
- ⭐ Satellite pustules around a moist erythematous fold rash support candidiasis.
- ⭐ Topical corticosteroid monotherapy can mask and worsen dermatophyte infection, producing tinea incognito.