Examination of skin often gives important clues to local or systemic diseases. The following features should be noted:

Color: It may be pale, flushed, cyanosed, yellow, etc.

Pigmentation: Pigmentation may occur in several diseases. Some common medical conditions associates with pigmentation are:

• Endocrine: Addison’s disease, Cushing’s disease, thyrotoxicosis.
• Deficiency: Pellagra, Kwashiorkor.
• Infections: Kala azar, chronic malaria, secondary syphilis, tuberculosis, leprosy, etc.
• Metabolic: Hemochromatosis.
• Skin disease: Neurofibromatosis, lichen planus, acanthosis nigricans, etc.
• Miscellaneous: Malignancy, pernicious anemia, exposure to sun rays or radiations.

Hypopigmentation: Hypopigmented patches may occur in leprosy, leukoderma, albinism, fungal infections of skin, etc.

Eruptions: Various types of eruptions may occur as follows:

• Macules: (Not raised above the skin). This may occur in typhoid, syphilis and purpura. If they are not generalized they are called roseollar.
• Papules: (Raised tiny nodules): This may occur in measles, chicken-pox, smallpox, and following drugs like sulfonamides.
• Pustules: These are papules containing pus.
• Nodules: (Large papules solitary projection from the skin). This may occur in erythema nodosum, leprosy, tuberculosis, secondary syphilis.
• Vesicles: (Small blisters). This may occur in herpes, chicken-pox and smallpox..
• Wheat: (Elevated patches on the skin with center paler than the periphery), Allergy.
• Café-Au-Lait patches: Dark brown patches resembling coffee in milk. They are considered significant if they are more than 5 in number. They are seen in:
  • Neurofibromatosis (regular outline without deep indentations).
  • Albright’s syndrome (irregular outline with deep indentations).

Hemorrhagic: Hemorrhage under the skin is classified as follows:

• Petechiae: Tiny hemorrhage less than 1 mm in diameter.
• Purpura: Hemorrhage 2-5 mm in diameter.
• Ecchymosis: Hemorrhage more than 5 cm in diameter.
• Hematoma: Hemorrhage large enough to produce elevation of skin.

Causes of hemorrhage under the skin:

• Deficiency: Vitamin deficiency, scurvy.
• Infection: Meningococcal meningitis, SBE, HIV.
• Hematological: Thrombocytopenia, acute leukemia, chronic lymphatic leukemia, chronic myeloid leukemia (in terminal phase) platelet dysfunction and aplastic anemia.

Type of Skin

• Dry skin: This is seen in myxedema and dehydration.
• Moist skin: This occurs when there is profuse perspiration as in shock, following myocardial infarction, crisis of pneumonia and thyrotoxicosis.
• Thick skin: This occurs in Myxedema, acromegaly and scleroderma.
• Thin skin: This occurs in old people and following wasting diseases.
• Pinched skin: suggests dehydration.

Hair: Changes in hair that occurs in some of the diseases are as follows:

• Falling of hair: Following infectious fevers e.g. typhoid.
• Patchy hair loss: Alopecia areata, syphilis.
• Loss of outer third of the eyebrows: Leprosy, Myxedema.
• Absence of axillary, pubic and facial hair: Hypopituitarism, hypogonadism.
• Excessive hair growth in women: Cushing’s syndrome, adrenocortical syndrome.