1. Dermatology
Approach
Fayza Rayes
MBBCh. Msc. MRCGP (UK)
Consultant Family Physician
Joint Program of Family & Community Medicine – Jeddah
www.fayzarayes.com
fayzarayes@yahoo.com

2. Prepared by dr. Fayza Rayes
Dermatology Approach:
1. Skin Rash
2. Skin pruritus
3. Mouth Condition
4. Palm & Sole Lesions
5. Nail Diseases
6. Nappy rash
7. Acne
8. Skin Pigmentations

3. Site and/or Distribution of The Lesions
 Generalized -- Viral exanthema & drugs
 Extensor -- Psoriasis, SLE,
-- Soles keratosis, ichthyosis
 Flexor -- Atopic dermatitis
 Lower extremities -- Erythema nodosum
-- Stasis dermatitis
 Sites of pressure -- Urticaria
 Site of trauma -- Psoriasis
-- Lichen planus,
-- Molluscum, Warts.

4. DD. Of Generalized Skin Rash
Drug eruption
Ampicillin rash
Viral exanthema
Measles

5. DD. Of Rash at Site of Trauma
Molluscum contaguasum
Psoriasis
Lichen
Warts.
planus

6. DD. Of Truncal Lesions Rash
Tinea versicolor Pityreasis rosea

7. Palms & Soles Conditions
Secondary syphilis

8. Dermatology
Arrangement of lesions
Arrangement Examples
• Isolated • Melanoma, Keratoacanthoma
• Scattered • Molluscam contagiosum, common warts
• Grouped • Lichen planer, insect bites
• Grouped of • Herpes simplex, herpes zoster
vesicles (Dermatomal )
• Annular (ring) • Tinea corporis, erythema multiform, drug
eruptions. Lupus erythomatosus, 2ry
syphilis, pityriasis rosea.
• Linear • Contact dermatitis, linear scleroderma,
keposi sarcoma

9. 1
Approach to Patient
with skin Rash

10. Diffuse Erythema
Differential Diagnosis
Infectious :
 Streptococcal infection (Scarlet fever)
 Staphylococcal infection (Toxic syndrome)
 Enteroviral infection
Non-infectious Causes:
– Allergy -- Vasodilatation
– Eczema -- Psoriasis
– Pityrosis rubra -- Lymphoma

11. Scarlet fever

12. Scarlet fever
Incubation period: 2 - 4 days
Days of illness
Complications:
Otitis media
Cervical adenitis
Rash Rhinitis
Sore throat Sinusitis
Rare:
Rheumatic fever
Acute nephritis

13. Maculo-papular Rash with Fever
Differential Diagnosis
Infection :
-- Measles -- Interoviral infection
-- Chickenpox -- Mononucleosis
-- Rubella -- Typhoid fever
-- Rubeola (Red measles) -- Secondary syphilis
-- Erythema infectious (5th) -- HIV (Primary)
-- Adenoviral exanthema -- Early meningitis
Non-infectious Causes :
-- Allergy -- Erythema multiform
-- SLE -- Erythema margenatum
-- Dermatomyositis -- Serum sickness
-- Drug rash

14. DD of Maculo-papular Rash with Fever
Chickenpox
Measles
Mononucleosis

15. Common Exanthematous Diseases
 Measles Maculopapular (5 days)
IP (10-14 days) Koplik’s spots, Prodromal illness,
complications are common.
 Rubella Macular --> maculopapular (3 ds)
IP (14-21 days) Malaise, little or no fever
 Chickenpox Maculer --> Papules --> Viscles -->
IP (1-14 days) Crust (7ds)
No other symptoms apart from rash
& low grade fever

16. Measles

17. Chickenpox
Incubation period: 1-14 days
:Complications
Secondary infection
:Rare
Encephalomyelitis

18. German measles
Incubation period: 14-21 days
Days of illness
Progression over 4 days
Maculopapular
Complications
Rash
Ing. Nodes Rare:
Malaise Arthritis
URTI Encephalitis
Purpura

19. DD. Of Generalized Skin Rash
This 32-year-old extravenous
drug abuser complained of
headaches and arthralgia &
maculopapular rash
This may occur shortly before
seroconversion in HIV-infected
individuals

20. DD of Maculo-papular Rash with Fever
Typhoid fever

21. Typhoid fever
Distribution of rose-spot rash: The typical rash of
typhoid fever may appear towards the end of the first week
but it has been recorded as late as the 20th day. It is present
in about half the adults with typhoid but is less common in
children. Rose spots are difficult to detect on dark skins.

22. DD of Maculo-papular Rash with Fever
Secondary syphilis
Erythema
infectious
(5th)
Early
meningitis

23. Early rash of meningitis:
Fleeting macular or papular rash.
This may occur alone or proceeding
hemorrhagic eruption by few hours

24. Suspected Meningococcal Infection
Immediate Treatment
 Adult and children older that 10 years
1200 mg Benzyl penicillin. IM
 Children aged 1-9 years
600 mg Benzyl penicillin. IM
 Infants aged less than 1 year
300 mg Benzyl penicillin. IM

25. Secondary Syphilis-rash
The rash may be papules
or pustules and crusts

26. DD of Papulosquamous Exanthems
Secondary syphilis

27. DD of Papulosquamous Exanthems
* Figure 5.
Drug eruption
* Figure 6.
Erythrodermic
drug eruption
5 6
* Figure 7.
Psoriasis
* Figure 8.
Lichen planus
7 8

28. DD of Papulosquamous
1 2
Exanthems
* Figure 1,2,3 & 4
Secondary syphilis
3 4
* Figure 5.
Drug eruption
* Figure 6.
5 6
Erythrodermic drug eruption
* Figure 7. Psoriasis
* Figure 8. Lichen planus
7 8

29. DD of Non-infectious Causes of
Maculo-papular Rash
SLE Erythema margenatum

30. DD of Non-infectious Causes of
Maculo-papular Rash
Steven-Johnson
Syndrome

31. Erythema Multiforme with
“bulls eyes” target lesions

32. Classification of Pustular Lesions
Local Infections :
• Bacterial : impetigo, folliculitis
• Viral : herpes simplex, herpes zoster,
• Fungal : dermatophyte infection, candida
Systemic Infections :
• Bacterial
• Meningococcaemia, Gonococcaemia & Staphylococcaemia
• Viral : varicella, enteroviral infection, HIV
Non-infective conditions :
Generalized pustular psoriasis or localized pustular psoriasis. Acne
vulgaris and rosacea, Eczema, Pemphigus, Porphyria, Erythema
multiform, Erythema bullosum.

33. DD of Pustular Lesions - Local Infections
Herpes simplex
Impetigo
herpes
zoster

34. DD of Pustular Lesions
Non-infective Conditions
Generalized pustular psoriasis
Erythema multiforme

35. DD of Pustular Lesions
Non-infective Conditions
Large, tense blisters in bullous pemphigoid

36. Pemphigus vulgaris demonstrating Bullous pemphigoid with
flaccid bullae which are easily tense vesicles and bullae
ruptured, resulting in multiple on an erythematous,
erosions and crusted plaques. urticarial base.

37. DD of Pustular Lesions
Non-infective Conditions
Linear blistering lesions in
primula dermatitis
Bullae occurring as
a reaction to flea
bites on the ankle

38. Blisters
Vasculobullous lesions on Phototoxic bullae
the palm, Characteristic associated with
of pompholyx nalidixic acid

39. DD of Pustular Lesions
Infective Conditions
Septicemia, probably gonococcal.

40. Purpuric or Petechial Rash
Differential Diagnosis
Infections :
 Bacteremia (with or without DIC)
o Infectious endocarditis
o Meningococcemia
o Gonococcemia or other pathogenic
bacteria
 Enteroviral infection
 Dengue fever
 Hepatitis
 Rubella
 Infectious Mononucleosis

41. DD of Purpuric or Petechial Rash
Rash of meningitis

42. Purpuric or Petechial Rash
Differential Diagnosis
Non-infectious causes :
 Allergy
 Low platelets of any cause
 Scurvy
 Henoch-Schonlain purpura
 Vasculitis
 Acute rheumatic fever
 Hyperglobulinemia

43. Purpuric Rash
Bruises
(ecehymoses) in
a patient with
coagulation
meningococcal defects due to
Henoch- septicemia - often acute hepatic
Schonlein disease sparse and need to be necrosis
looked for carefully

44. Purpuric Rash
Vasculitis. Palpable
purpuric papules on
the lower legs are
seen in this patient
with coetaneous small
vessel vasculitis.

45. Patient with rash
Warning Presentation
 Associated symptoms suggestive of serious illness.
 Purpuric or petechial rash
 Generalized pustular rash
 Infection in dangerous area
E.g.. eyes, dangerous area of the face.
 Very toxic patient

46. 2
Approach to Patient
with skin Pruritus

47. Pruritus
History
 Duration, localization & character of the itch.
 Provocating factors
 Diurnal variation
 Sleep disturbance
 Occupational history
 Itchy contact

48. Pruritus
Examination & warning presentation
Examination :
 Patient general condition
 Characteristic of the skin lesion e.g.
o Burrows of scabies
o Lichenification of eczema
o Skin discoloration
o Scaly lesion
Warning presentation :
 No overt skin disease
 Ill elderly patient (cancer)

49. Systemic Causes of Pruritus
1. Cholestasis :
-- Primarily biliary cirrhosis -- Pregnancy
-- Extrahepatic obstruction -- Drugs e.g. Contracep.
2. Endocrine :
-- Thyrotoxiosis -- Myxoedema
-- Hyperparathyroidism -- DM
3. Hematological / Myeloproliferative :
-- Iron deficiency -- Polycythemia
-- Hodgkin’s disease -- Multiple myeloma
4. Chronic Renal Failure :
5. Malignancy / Miscellaneous :
-- Gout -- Psychological -- Old age.

50. Some common dermatological
conditions associated with itching
Severe Moderate
 Infestation : Scabies, lice  Psoriasis
 Insect bites  Fungal infections
 Eczema  Pityriasis rosea
 Articaria  Pemphigiod
 Dermatitis herpetiformis  Xerosis (dry skin)
 Lichen planus Localized Itching
 Lichen simplex  Pruritus ani
 Drug reactions  Pruritus vulvae

51. Some common dermatological
conditions associated with itching
Severe
 Infestation : Scabies, lice
 Insect bites
 Eczema
 Urticaria
 Dermatitis herpetiformis
 Lichen planus
 Lichen simplex
 Drug reactions

52. The head louse: Head lice need relatively
Physical evidence of prolonged head-to-bead
living lice is required contact. Estimates suggest it
before treatment takes of least 30 seconds for
begins, but they con lice to move from one beside
be difficult to detect to another

53. Dermatological conditions associated with severe itching
Childhood atopic eczema. Facial atopic eczema.

54. Dermatological conditions associated with severe itching
Eczema
Hyperkeratotic hand Vesicular hand dermatitis
eczema. (pompholyx).
Infected hand eczema (Ring) dermatitis

55. Dermatological conditions associated with severe itching
Urticaria

56. Dermatological conditions associated with severe itching
Urticaria showing charac-
teristic discrete and confluent,
edematous, erythematous
papules and plaques.

57. Dermatological conditions associated with severe itching
Scabies
Widespread pruritis rash of scabies. Characteristic burrow of
scabies..

58. Dermatological conditions associated with severe itching
Dermatitis herpetiformis
Herpes simplex infection associated with atopic dermatitis
It was misdiagnosed as pyoderma and treated with
antibiotics for more than 2 weeks

59. Dermatological conditions associated with severe itching
Dermatitis herpetiformis manifested by
pruritic, grouped vesicles in a typical location.
The vesicles are often excoriated and may occur
on knees, buttocks, and posterior scalp.

60. Dermatological conditions associated with severe itching
lichen planus
Flat-topped violaceous Wickham's striae
papules of lichen
planus. (lichen planus).

61. Dermatological conditions associated with severe itching
Lichen planus showing multiple
flat-topped, violaceous papules and
plaques. Nail dystrophy as seen in
this patient's thumbnail may also he a
feature.

62. Dermatological conditions associated with severe itching
Lichen simplex
lichen simplex Lichen simper of Lichenification
chronicus scrotum from constant
rubbing

63. Dermatological conditions associated with severe itching
Angio-edema
Most drugs have the
potential to cause
angio-edema,
urticaria, pruritus
and maculopopular
rash

64. Dermatological conditions associated with severe itching
Widespread urticaria Severe angio-oedema

65. Some common dermatological
conditions associated with itching
Moderate:
 Psoriasis
 Fungal infections
 Pityriasis rosea
 Pemphigiod
 Xerosis (dry skin)

66. Some common dermatological conditions associated
with moderate itching
Pityriasis rosea
Psoriasis

67. Common Cause of
Local Itching
Pruritus ani - perianai
dermatitis.

68. Herpes simplex of the anus.

69. 3
Mouth Conditions

70. Month Ulcers
Differential Diagnosis
 Trauma (dentures)  Erythema multiform
(from drugs)
 Aphthous ulcers
 Pemphigus
 Candida infection
 Lichen planus
 Herpes simplex  Carcinoma

71. DD. Of Oral
Conditions
Erythema multiform
Aphthous ulcers
Lichen planus

72. Erythema
multiforme
Bullous erythema
multiforme lesions of palm.
Typical target lesions
Erythema multiforme:
mucosal involvement

73. Aphthus Ulcer
Aphthous ulcers: Small ulcers, 1 – 4 mm in diameter may
occur on healthy persons as a recurrent, painful, self-
limiting problem lasting five to six days, aetiology unknown.
An aphthous-like ulcer may occur on the pharynx in
infectious mononucleosis

74. DD. Of Oral
Conditions
Aphthus Ulcer
Pemphigus

75. Oral thrush Leukoplakia

76. lichen planus on the
tongue, resembling
leukoplakia

77. Iron deficiency anemia
Smooth tongue
Angular stomatitis

78. 1 2
Differential Diagnosis of
Mucous Membrane Lesions
Figure 1. Secondary syphilis
3 4
Figure 2. Lichen planus
Figure 3. Scrotal tongue
Figure 4. Geographic tongue
5 6
Figure 5. Aphthus ulcer
Figure 6. Black hairy tongue
7 8 Figure 7. Pyogenic granuloma
Figure 8. Median rhomboid
glossitis

79. 1 3
2 4 5
1) Angular stomatitis 3) Carcinoma of lip 5) Peutz-Jeghers
2) Herpes labialis 4) Hereditary syndrome
hemorrhagic
telangiectasia

80. 4
Palm & Sole
Lesions

81. DD. Of Acral Tinea pedis
Lesions
plantar warts
dyshydrotic dermatitis

82. DD. Of Palm
& Sole
Lesions
Tinia pedis Unilateral scaling of the
palm(tinea manuum).
Dermatophyte
infection spreading
out from the toes

83. DD. Of Palm
& Sole
Lesions
Pustular psoriasis on sole of foot
Psoriasis nail with ridging and pitting

84. 5
Nail Diseases

85. Differential Diagnosis
1 2 of Nail Diseases
* Figure 1. Fungal infection
* Figure 2. Paronychia.
3 4
* Figure 3. Posttraumatic
hematoma
* Figure 4. Ingrown toenail
5 6
* Figure 5. Onychogryposis
* Figure 6. Lichen planus
* Figure 7& 8. Psoriasis
7 8

86. Splinter hemorrhages of the nails

87. Tinea Infection

88. Longitudinal section of distal phalanx to show
nail.Brittle nails may be a sign of peripheral vascular
insufficiency, anemia or hypothyroidism

89. 6
Nappy Rash

90. Nappy Rash
Differential Diagnosis & Management
 Contact dermatitis -- Emollient, frequent changing
& cleaning.
-- Zincoxide paste + Topical steroids
 Atopic dermatitis -- Emollient, Local steroids, Systemic
antihistamine for pruritus antibiotics.
 Seborrhoeic dermatitis -- Local steroids / Antiseptic.
Cleaning cream.
 Candiasis -- Topical antifungal e.g.. Nystatin &
Unidazole or Hydrocortisone /
Unidazole combination.

91. Napkin rash
Napkin dermatitis Candidiasis
Erythema and ulcers on expose Bright red area (involving flexures)
surfaces (sparing flexures) spread from prenial area

92. Napkin Eruptions
Sebarrhoeic dermatitis of infants
Ammoniacal napkin rash

93. Napkin Eruptions
Granuloma Psoriasiform
Candidal intertrigo gluteale napkin rash
infantum
(candida).

94. 7
Acne

95. Acne - Lesions / Stages
 Primary comedones
 Mildly inflammatory : Comedones and papules
 Moderate or severe Inflammatory :
Many papules , pustules & some cysts
 Conglobate abscesses (large cysts) & severe scarring

96. Acne

97. Acne

98. Acne
Gray discoloration in the numerous old acne
scar of the face as side effect of Minocycline

99. Rosacea is easily confused with acne, acne
vulgaris tends to occur in a younger age group
and comedones are usually present. Comedones
are not seen in rosacea

100. Typical case of rosacea: small papules and
pustules on an erythematous, telangiectatic
background. The most common sites are the
central cheeks, forehead, tip of the nose and chin

101. Acne rosacea. Commoner in Rhinophyma. Enlargement of
women, esp. those with Celtic the nose due to hypertrophy of
skin. Cruciate distribution sebaceous glands.

102. Acne Therapy Guide
Lesion / Stage Therapy
• Primary comedones • Retinoic acid cream / gel
• Mildly inflammatory : • Topical antibiotic or benzoyl
Comedones and peroxide lotion or gel
papules (sometimes retinoic acid)
• Benzoyl peroxide & oral or
• Moderate or severe
Inflammatory : topical antibiotic
(sometimes retinoic acid)
Many papules &
pustules, some cysts • Referral of treatment
failures
• Conglobate abscesses, • Referral
severe scarring

103. 8
Skin
Pigmentation

104. Differential Diagnosis of Pigmented Skin Lesions
* Figure 1.
Pigmented
basal cell
carcinoma
* Figure 2.
1 2 Blue nevus
* Figure 3.
Lentigo
maligna
* Figure 4.
Superficial
3 4 spreading
melanoma

105. Differential Diagnosis of Pigmented Skin Lesions
* Figure 5.
Nodular
melanoma
5 6 * Figure 6.
Seborrhoeic
keratosis
* Figure 7.
Dermatofibroma
* Figure 8.
Angiokeratoma
7 8

106. Differential Diagnosis of
Pigmented Skin Lesions
1 •Figure 1. Pigmented basal cell
2
carcinoma
•Figure 2. Blue nevus
•Figure 3. Lentigo maligna
3 4
•Figure 4. Superficial spreading
melanoma
5 6 * Figure 5. Nodular melanoma
* Figure 6. Seborrhoeic keratosis
* Figure 7. Dermatofibroma
7 8 * Figure 8. Angiokeratoma

107. Oral Kaposi’s Sarcoma
Coetaneous Kaposi’s
Sarcoma in a homosexual
man

108. Skin Manifestation of
Internal Malignancy
Fig. 1 Acanthosis nigricans
1 2 in a patient with underlying
malignancy.
Fig. 2 Acanthosis nigricans
(benign type).
Fig. 3 Acquired ichthyosis
with underlying lymphoma.
Fig. 4 Migratory
thrombophlebitis.
3 4