Lanigan part 2

Question 1

Angioedema

Answer 1

Cause: Bradykinin

Screen with C4 (↓)

Decreased C1 level points to acquired C1 esterase deficiency rather than the hereditary type (It’s new and the body can’t keep up!)
Increased consumption of C1q followed by C2 and C4 results in subsequent release of vasoactive peptides.

Question 2

Erythema Multiforme/SJS/TEN

Answer 2

Erythema multiforme – Typical targets or papules, minimal mucous membrane involvement; epidermal detachment involves <10% body surface area.

SJS- Blisters on trunk and face, confluent purpuric macules + severe mucous membrane erosion; epidermal detachment <10% BSA.

TEN - Begins with severe mucosal erosions; progresses to diffuse, generalized detachment of the epidermis, >30% BSA.

Question 3

A man with bull’s eye lesions spends a lot of time a wooded area with known Ixodes scapularis.
What might this patient develop in the near future?

A. Bell’s palsy
B. Renal cancer
C. Thrombocytopenia
D Streptococcus
E. Urethritis

Answer 3

Lyme disease

Stage I: Flu syndrome with rash (ECM)
Stage II: Dissemination: heart, joints, nerves and skin (* heart block, * Bell’s palsy,
migratory arthralgias, ECM)
Stage III: Late: joints and CNS and PNS (* oligoarthritis, * encephalitis/memory loss
- sleep disturbances, neuropathies/* paresthesias)
Be aware of Southern Tick-associated rash illness (STARI)- possible cause is Borrelia lonestari

Question 4

Cellulitis

Answer 4

Erythema, swelling, and pain that may rapidly expand and progress to systemic symptoms – chills, fever, malaise.
Skin is tender to touch.
Septicemia and shock may develop.
Common causes: streptococci, Staphylococcus aureus including MRSA.
Oral abx for mild cases, or IV abx if more severe.

Question 5

Pemphigus vs. Pemphigoid

Answer 5

Pemphigus:
Flaccid blisters
Blister erosion
Histopathology shows suprabasilar separation
Nikolsky sign (rubbing skin leads to blisters)
Can be medication induced

Pemphigoid
Tense blisters
Histopathology shows  subepidermal blisters
Pruritic 
Can be medication induced

Question 6

Molluscum Contagiosum

Answer 6

Caused by a poxvirus.
Most common in children.
In adults, it may be sexually transmitted.
Incubation period: 2 weeks – 6 months.
Spontaneous resolution averages 13 months, but may take several years.

Question 7

Lichen Planus

Answer 7

Purple, pruritic, polygonal papules
Affects flexural surfaces, esp. wrists & ankles
White plaques on mucous membranes
Nails can also be affected
Usually idiopathic, but there is an association with Hep. C and certain medications
- Gold salts, captopril, HCTZ, hydroxychloroquine, NSAID’s, sulfonamides, tetracycline

Question 8

Scabies

Answer 8

Severe pruritus
Infestation with Sarcoptes scabiei
Burrows, vesicles, and pustules. Areas may also become crusted and hyperkeratotic.
Adult pattern: rash in finger webs, wrists, at waistband, axilla, penis & scrotum in men.
In children, the elderly, or the immunosuppressed, scabies may be diffuse.

Question 9

Lofgren’s Syndrome

Answer 9

= Erythema nodosum with hilar

lymphadenopathy and acute polyarthritis - Sarcoid

Question 10

Mnemonic for E. nodosum

Answer 10

= “BUMPS” = 
Boeck’s Sarcoid (HLA-DRB1*03); Behcet’s
Ulcerative colitis and Crohn’s
Mycoses – TB, Histo, Cocci, Blasto, etc
Pills – BCPs, sulfa, etc
Streptococcus – Yersinia, Chlamydia, Mycoplasma, Salmonella, Campylobacter, etc

Question 11

Abscesses/Furuncles/Carbuncles

Answer 11

These require incision and drainage.
Obtain a culture of the purulent drainage, to check antibiotic senstivity.
Use systemic antibiotics if:
- Immunosuppressed pt.
- Cellulitis
- Fever or other systemic symptoms
- Size >5 cm or multiple abscesses
Antistaphylococcal antibiotics are recommended if indicated (consider MRSA).

Question 12

Subacute Cutaneous Lupus Erythematosus may occur with

Answer 12

SLE,

Sjögrens, or deficiency of the 2nd component of complement, or be drug induced.

Question 13

Which antibody would you expect in this photosensitive patient?

A. Histone
B. Smooth muscle
C. RO/SSA 
D. Microsomal
E. Double stranded DNA

Answer 13

Anti-Ro/SSA associated with photosensitive rashes & neonatal SLE (including heart block).

Question 14

Venous Leg Ulcers

Answer 14

Risk factors:

• Venous stasis/venous insufficiency
• Higher BMI
• History of DVT
• Number of pregnancies
• Physical inactivity

Rule out arterial insufficiency – check ABI
- Abnormal ABI <0.7

Tx: leg elevation, compression stockings, wound care

Question 15

Alopecias

Answer 15

Androgenic alopecia – male pattern baldness

Alopecia areata – autoimmune disorder causing hairless patches

Tinea capitis – Fungal; scaly areas→ with broken-off hairs

Telogen effluvium – diffuse hair thinning due to shift from growing→resting phase in follicles, often 3 months after trauma

Trichotillomania – due to hair pulling; short, broken hairs seen within area of hair loss

Question 16

Drug Reaction with Eosinophilia and Systemic Syndrome

Answer 16

= DRESS
1. 2-6 weeks after start of a new medicine
2. Progression from acral edema to generalized rash to pinpoint
pustules and desquamation
3. Fever, lymphadenopathy, hepatomegaly and abnormal LFTs
4. An IL5 disease.

Question 17

Skin of Color

Answer 17

Inflammatory rashes may be more difficult to see.
Traumatic or inflammatory changes may cause hyperpigmentation.
Inflammation may also
cause hypopigmentation.

Question 18

Keloids

Answer 18

Keloids are more common in black persons, although they can occur in any race.

Due to dermal collagen overgrowth.

Scarring extends past the border of the original injury.

Tx: intralesional glucocorticoids, laser tx, intralesional chemotherapy, radiation therapy.

Question 19

Skin Cancer

Answer 19

Skin cancer is less common in people with more pigmented skin, but still occurs.
Squamous cell CA may develop in areas of chronic inflammation or scarring.
Acral lentiginous melanoma
- Affects palms, soles, nails.
- Most common type of
melanoma in people of Asian
or African descent